diff --git a/lib/spack/spack/test/architecture.py b/lib/spack/spack/test/architecture.py
index 1a67850aaf..becb221045 100644
--- a/lib/spack/spack/test/architecture.py
+++ b/lib/spack/spack/test/architecture.py
@@ -216,10 +216,12 @@ def test_satisfy_strict_constraint_when_not_concrete(architecture_tuple, constra
     str(archspec.cpu.host().family) != "x86_64", reason="tests are for x86_64 uarch ranges"
 )
 def test_concretize_target_ranges(root_target_range, dep_target_range, result, monkeypatch):
-    spec = Spec(f"a %gcc@10 foobar=bar target={root_target_range} ^b target={dep_target_range}")
+    spec = Spec(
+        f"pkg-a %gcc@10 foobar=bar target={root_target_range} ^pkg-b target={dep_target_range}"
+    )
     with spack.concretize.disable_compiler_existence_check():
         spec.concretize()
-    assert spec.target == spec["b"].target == result
+    assert spec.target == spec["pkg-b"].target == result
 
 
 @pytest.mark.parametrize(
diff --git a/lib/spack/spack/test/build_environment.py b/lib/spack/spack/test/build_environment.py
index cbccbc429e..cf4cd111ff 100644
--- a/lib/spack/spack/test/build_environment.py
+++ b/lib/spack/spack/test/build_environment.py
@@ -437,14 +437,14 @@ def test_parallel_false_is_not_propagating(default_mock_concretization):
     # a foobar=bar (parallel = False)
     # |
     # b (parallel =True)
-    s = default_mock_concretization("a foobar=bar")
+    s = default_mock_concretization("pkg-a foobar=bar")
 
     spack.build_environment.set_package_py_globals(s.package)
-    assert s["a"].package.module.make_jobs == 1
+    assert s["pkg-a"].package.module.make_jobs == 1
 
-    spack.build_environment.set_package_py_globals(s["b"].package)
-    assert s["b"].package.module.make_jobs == spack.build_environment.determine_number_of_jobs(
-        parallel=s["b"].package.parallel
+    spack.build_environment.set_package_py_globals(s["pkg-b"].package)
+    assert s["pkg-b"].package.module.make_jobs == spack.build_environment.determine_number_of_jobs(
+        parallel=s["pkg-b"].package.parallel
     )
 
 
@@ -540,7 +540,7 @@ def test_dirty_disable_module_unload(config, mock_packages, working_env, mock_mo
     """Test that on CRAY platform 'module unload' is not called if the 'dirty'
     option is on.
     """
-    s = spack.spec.Spec("a").concretized()
+    s = spack.spec.Spec("pkg-a").concretized()
 
     # If called with "dirty" we don't unload modules, so no calls to the
     # `module` function on Cray
diff --git a/lib/spack/spack/test/build_systems.py b/lib/spack/spack/test/build_systems.py
index 8342ecc6e8..66aea550cb 100644
--- a/lib/spack/spack/test/build_systems.py
+++ b/lib/spack/spack/test/build_systems.py
@@ -97,7 +97,7 @@ def test_negative_ninja_check(self, input_dir, test_dir, concretize_and_setup):
 @pytest.mark.usefixtures("config", "mock_packages")
 class TestAutotoolsPackage:
     def test_with_or_without(self, default_mock_concretization):
-        s = default_mock_concretization("a")
+        s = default_mock_concretization("pkg-a")
         options = s.package.with_or_without("foo")
 
         # Ensure that values that are not representing a feature
@@ -129,7 +129,7 @@ def activate(value):
         assert "--without-lorem-ipsum" in options
 
     def test_none_is_allowed(self, default_mock_concretization):
-        s = default_mock_concretization("a foo=none")
+        s = default_mock_concretization("pkg-a foo=none")
         options = s.package.with_or_without("foo")
 
         # Ensure that values that are not representing a feature
diff --git a/lib/spack/spack/test/cmd/ci.py b/lib/spack/spack/test/cmd/ci.py
index 2695b7381f..1a435eef79 100644
--- a/lib/spack/spack/test/cmd/ci.py
+++ b/lib/spack/spack/test/cmd/ci.py
@@ -102,24 +102,24 @@ def test_specs_staging(config, tmpdir):
 
 """
     builder = repo.MockRepositoryBuilder(tmpdir)
-    builder.add_package("g")
-    builder.add_package("f")
-    builder.add_package("e")
-    builder.add_package("d", dependencies=[("f", None, None), ("g", None, None)])
-    builder.add_package("c")
-    builder.add_package("b", dependencies=[("d", None, None), ("e", None, None)])
-    builder.add_package("a", dependencies=[("b", None, None), ("c", None, None)])
+    builder.add_package("pkg-g")
+    builder.add_package("pkg-f")
+    builder.add_package("pkg-e")
+    builder.add_package("pkg-d", dependencies=[("pkg-f", None, None), ("pkg-g", None, None)])
+    builder.add_package("pkg-c")
+    builder.add_package("pkg-b", dependencies=[("pkg-d", None, None), ("pkg-e", None, None)])
+    builder.add_package("pkg-a", dependencies=[("pkg-b", None, None), ("pkg-c", None, None)])
 
     with repo.use_repositories(builder.root):
-        spec_a = Spec("a").concretized()
+        spec_a = Spec("pkg-a").concretized()
 
         spec_a_label = ci._spec_deps_key(spec_a)
-        spec_b_label = ci._spec_deps_key(spec_a["b"])
-        spec_c_label = ci._spec_deps_key(spec_a["c"])
-        spec_d_label = ci._spec_deps_key(spec_a["d"])
-        spec_e_label = ci._spec_deps_key(spec_a["e"])
-        spec_f_label = ci._spec_deps_key(spec_a["f"])
-        spec_g_label = ci._spec_deps_key(spec_a["g"])
+        spec_b_label = ci._spec_deps_key(spec_a["pkg-b"])
+        spec_c_label = ci._spec_deps_key(spec_a["pkg-c"])
+        spec_d_label = ci._spec_deps_key(spec_a["pkg-d"])
+        spec_e_label = ci._spec_deps_key(spec_a["pkg-e"])
+        spec_f_label = ci._spec_deps_key(spec_a["pkg-f"])
+        spec_g_label = ci._spec_deps_key(spec_a["pkg-g"])
 
         spec_labels, dependencies, stages = ci.stage_spec_jobs([spec_a])
 
@@ -1256,7 +1256,7 @@ def test_ci_generate_override_runner_attrs(
 spack:
   specs:
     - flatten-deps
-    - a
+    - pkg-a
   mirrors:
     some-mirror: https://my.fake.mirror
   ci:
@@ -1273,12 +1273,12 @@ def test_ci_generate_override_runner_attrs(
         - match:
             - dependency-install
         - match:
-            - a
+            - pkg-a
           build-job:
             tags:
               - specific-a-2
         - match:
-            - a
+            - pkg-a
           build-job-remove:
             tags:
               - toplevel2
@@ -1338,8 +1338,8 @@ def test_ci_generate_override_runner_attrs(
             assert global_vars["SPACK_CHECKOUT_VERSION"] == git_version or "v0.20.0.test0"
 
             for ci_key in yaml_contents.keys():
-                if ci_key.startswith("a"):
-                    # Make sure a's attributes override variables, and all the
+                if ci_key.startswith("pkg-a"):
+                    # Make sure pkg-a's attributes override variables, and all the
                     # scripts.  Also, make sure the 'toplevel' tag doesn't
                     # appear twice, but that a's specific extra tag does appear
                     the_elt = yaml_contents[ci_key]
@@ -1798,7 +1798,7 @@ def test_ci_generate_read_broken_specs_url(
     tmpdir, mutable_mock_env_path, install_mockery, mock_packages, monkeypatch, ci_base_environment
 ):
     """Verify that `broken-specs-url` works as intended"""
-    spec_a = Spec("a")
+    spec_a = Spec("pkg-a")
     spec_a.concretize()
     a_dag_hash = spec_a.dag_hash()
 
@@ -1824,7 +1824,7 @@ def test_ci_generate_read_broken_specs_url(
 spack:
   specs:
     - flatten-deps
-    - a
+    - pkg-a
   mirrors:
     some-mirror: https://my.fake.mirror
   ci:
@@ -1832,9 +1832,9 @@ def test_ci_generate_read_broken_specs_url(
     pipeline-gen:
     - submapping:
       - match:
-          - a
+          - pkg-a
           - flatten-deps
-          - b
+          - pkg-b
           - dependency-install
         build-job:
           tags:
diff --git a/lib/spack/spack/test/cmd/common/arguments.py b/lib/spack/spack/test/cmd/common/arguments.py
index e889fe55d8..d48f3f4f6b 100644
--- a/lib/spack/spack/test/cmd/common/arguments.py
+++ b/lib/spack/spack/test/cmd/common/arguments.py
@@ -81,14 +81,14 @@ def test_match_spec_env(mock_packages, mutable_mock_env_path):
     """
     # Initial sanity check: we are planning on choosing a non-default
     # value, so make sure that is in fact not the default.
-    check_defaults = spack.cmd.parse_specs(["a"], concretize=True)[0]
+    check_defaults = spack.cmd.parse_specs(["pkg-a"], concretize=True)[0]
     assert not check_defaults.satisfies("foobar=baz")
 
     e = ev.create("test")
-    e.add("a foobar=baz")
+    e.add("pkg-a foobar=baz")
     e.concretize()
     with e:
-        env_spec = spack.cmd.matching_spec_from_env(spack.cmd.parse_specs(["a"])[0])
+        env_spec = spack.cmd.matching_spec_from_env(spack.cmd.parse_specs(["pkg-a"])[0])
         assert env_spec.satisfies("foobar=baz")
         assert env_spec.concrete
 
@@ -96,12 +96,12 @@ def test_match_spec_env(mock_packages, mutable_mock_env_path):
 @pytest.mark.usefixtures("config")
 def test_multiple_env_match_raises_error(mock_packages, mutable_mock_env_path):
     e = ev.create("test")
-    e.add("a foobar=baz")
-    e.add("a foobar=fee")
+    e.add("pkg-a foobar=baz")
+    e.add("pkg-a foobar=fee")
     e.concretize()
     with e:
         with pytest.raises(ev.SpackEnvironmentError) as exc_info:
-            spack.cmd.matching_spec_from_env(spack.cmd.parse_specs(["a"])[0])
+            spack.cmd.matching_spec_from_env(spack.cmd.parse_specs(["pkg-a"])[0])
 
     assert "matches multiple specs" in exc_info.value.message
 
@@ -109,16 +109,16 @@ def test_multiple_env_match_raises_error(mock_packages, mutable_mock_env_path):
 @pytest.mark.usefixtures("config")
 def test_root_and_dep_match_returns_root(mock_packages, mutable_mock_env_path):
     e = ev.create("test")
-    e.add("b@0.9")
-    e.add("a foobar=bar")  # Depends on b, should choose b@1.0
+    e.add("pkg-b@0.9")
+    e.add("pkg-a foobar=bar")  # Depends on b, should choose b@1.0
     e.concretize()
     with e:
         # This query matches the root b and b as a dependency of a. In that
         # case the root instance should be preferred.
-        env_spec1 = spack.cmd.matching_spec_from_env(spack.cmd.parse_specs(["b"])[0])
+        env_spec1 = spack.cmd.matching_spec_from_env(spack.cmd.parse_specs(["pkg-b"])[0])
         assert env_spec1.satisfies("@0.9")
 
-        env_spec2 = spack.cmd.matching_spec_from_env(spack.cmd.parse_specs(["b@1.0"])[0])
+        env_spec2 = spack.cmd.matching_spec_from_env(spack.cmd.parse_specs(["pkg-b@1.0"])[0])
         assert env_spec2
 
 
diff --git a/lib/spack/spack/test/cmd/concretize.py b/lib/spack/spack/test/cmd/concretize.py
index 914f0fe6af..d528cad258 100644
--- a/lib/spack/spack/test/cmd/concretize.py
+++ b/lib/spack/spack/test/cmd/concretize.py
@@ -51,8 +51,8 @@ def test_concretize_root_test_dependencies_are_concretized(unify, mutable_mock_e
 
     with ev.read("test") as e:
         e.unify = unify
-        add("a")
-        add("b")
+        add("pkg-a")
+        add("pkg-b")
         concretize("--test", "root")
         assert e.matching_spec("test-dependency")
 
diff --git a/lib/spack/spack/test/cmd/deconcretize.py b/lib/spack/spack/test/cmd/deconcretize.py
index 30e39604bf..5cb61d70be 100644
--- a/lib/spack/spack/test/cmd/deconcretize.py
+++ b/lib/spack/spack/test/cmd/deconcretize.py
@@ -15,26 +15,26 @@
 def test_env(mutable_mock_env_path, config, mock_packages):
     ev.create("test")
     with ev.read("test") as e:
-        e.add("a@2.0 foobar=bar ^b@1.0")
-        e.add("a@1.0 foobar=bar ^b@0.9")
+        e.add("pkg-a@2.0 foobar=bar ^pkg-b@1.0")
+        e.add("pkg-a@1.0 foobar=bar ^pkg-b@0.9")
         e.concretize()
         e.write()
 
 
 def test_deconcretize_dep(test_env):
     with ev.read("test") as e:
-        deconcretize("-y", "b@1.0")
+        deconcretize("-y", "pkg-b@1.0")
         specs = [s for s, _ in e.concretized_specs()]
 
     assert len(specs) == 1
-    assert specs[0].satisfies("a@1.0")
+    assert specs[0].satisfies("pkg-a@1.0")
 
 
 def test_deconcretize_all_dep(test_env):
     with ev.read("test") as e:
         with pytest.raises(SpackCommandError):
-            deconcretize("-y", "b")
-        deconcretize("-y", "--all", "b")
+            deconcretize("-y", "pkg-b")
+        deconcretize("-y", "--all", "pkg-b")
         specs = [s for s, _ in e.concretized_specs()]
 
     assert len(specs) == 0
@@ -42,27 +42,27 @@ def test_deconcretize_all_dep(test_env):
 
 def test_deconcretize_root(test_env):
     with ev.read("test") as e:
-        output = deconcretize("-y", "--root", "b@1.0")
+        output = deconcretize("-y", "--root", "pkg-b@1.0")
         assert "No matching specs to deconcretize" in output
         assert len(e.concretized_order) == 2
 
-        deconcretize("-y", "--root", "a@2.0")
+        deconcretize("-y", "--root", "pkg-a@2.0")
         specs = [s for s, _ in e.concretized_specs()]
 
     assert len(specs) == 1
-    assert specs[0].satisfies("a@1.0")
+    assert specs[0].satisfies("pkg-a@1.0")
 
 
 def test_deconcretize_all_root(test_env):
     with ev.read("test") as e:
         with pytest.raises(SpackCommandError):
-            deconcretize("-y", "--root", "a")
+            deconcretize("-y", "--root", "pkg-a")
 
-        output = deconcretize("-y", "--root", "--all", "b")
+        output = deconcretize("-y", "--root", "--all", "pkg-b")
         assert "No matching specs to deconcretize" in output
         assert len(e.concretized_order) == 2
 
-        deconcretize("-y", "--root", "--all", "a")
+        deconcretize("-y", "--root", "--all", "pkg-a")
         specs = [s for s, _ in e.concretized_specs()]
 
     assert len(specs) == 0
diff --git a/lib/spack/spack/test/cmd/env.py b/lib/spack/spack/test/cmd/env.py
index 882e5f5356..d54e653beb 100644
--- a/lib/spack/spack/test/cmd/env.py
+++ b/lib/spack/spack/test/cmd/env.py
@@ -27,7 +27,9 @@
 import spack.package_base
 import spack.paths
 import spack.repo
+import spack.store
 import spack.util.spack_json as sjson
+import spack.util.spack_yaml
 from spack.cmd.env import _env_create
 from spack.main import SpackCommand, SpackCommandError
 from spack.spec import Spec
@@ -346,7 +348,7 @@ def test_env_install_two_specs_same_dep(install_mockery, mock_fetch, tmpdir, cap
                 """\
 spack:
   specs:
-  - a
+  - pkg-a
   - depb
 """
             )
@@ -365,8 +367,8 @@ def test_env_install_two_specs_same_dep(install_mockery, mock_fetch, tmpdir, cap
     depb = spack.store.STORE.db.query_one("depb", installed=True)
     assert depb, "Expected depb to be installed"
 
-    a = spack.store.STORE.db.query_one("a", installed=True)
-    assert a, "Expected a to be installed"
+    a = spack.store.STORE.db.query_one("pkg-a", installed=True)
+    assert a, "Expected pkg-a to be installed"
 
 
 def test_remove_after_concretize():
@@ -635,7 +637,7 @@ def test_env_view_external_prefix(tmp_path, mutable_database, mock_packages):
         """\
 spack:
   specs:
-  - a
+  - pkg-a
   view: true
 """
     )
@@ -643,9 +645,9 @@ def test_env_view_external_prefix(tmp_path, mutable_database, mock_packages):
     external_config = io.StringIO(
         """\
 packages:
-  a:
+  pkg-a:
     externals:
-    - spec: a@2.0
+    - spec: pkg-a@2.0
       prefix: {a_prefix}
     buildable: false
 """.format(
diff --git a/lib/spack/spack/test/cmd/install.py b/lib/spack/spack/test/cmd/install.py
index 8eb3bfedb8..dbcea335c8 100644
--- a/lib/spack/spack/test/cmd/install.py
+++ b/lib/spack/spack/test/cmd/install.py
@@ -88,7 +88,7 @@ def check(pkg):
         assert pkg.run_tests
 
     monkeypatch.setattr(spack.package_base.PackageBase, "unit_test_check", check)
-    install("--test=all", "a")
+    install("--test=all", "pkg-a")
 
 
 def test_install_package_already_installed(
@@ -570,61 +570,58 @@ def test_cdash_upload_build_error(tmpdir, mock_fetch, install_mockery, capfd):
 @pytest.mark.disable_clean_stage_check
 def test_cdash_upload_clean_build(tmpdir, mock_fetch, install_mockery, capfd):
     # capfd interferes with Spack's capturing of e.g., Build.xml output
-    with capfd.disabled():
-        with tmpdir.as_cwd():
-            install("--log-file=cdash_reports", "--log-format=cdash", "a")
-            report_dir = tmpdir.join("cdash_reports")
-            assert report_dir in tmpdir.listdir()
-            report_file = report_dir.join("a_Build.xml")
-            assert report_file in report_dir.listdir()
-            content = report_file.open().read()
-            assert "</Build>" in content
-            assert "<Text>" not in content
+    with capfd.disabled(), tmpdir.as_cwd():
+        install("--log-file=cdash_reports", "--log-format=cdash", "pkg-a")
+        report_dir = tmpdir.join("cdash_reports")
+        assert report_dir in tmpdir.listdir()
+        report_file = report_dir.join("pkg-a_Build.xml")
+        assert report_file in report_dir.listdir()
+        content = report_file.open().read()
+        assert "</Build>" in content
+        assert "<Text>" not in content
 
 
 @pytest.mark.disable_clean_stage_check
 def test_cdash_upload_extra_params(tmpdir, mock_fetch, install_mockery, capfd):
     # capfd interferes with Spack's capture of e.g., Build.xml output
-    with capfd.disabled():
-        with tmpdir.as_cwd():
-            install(
-                "--log-file=cdash_reports",
-                "--log-format=cdash",
-                "--cdash-build=my_custom_build",
-                "--cdash-site=my_custom_site",
-                "--cdash-track=my_custom_track",
-                "a",
-            )
-            report_dir = tmpdir.join("cdash_reports")
-            assert report_dir in tmpdir.listdir()
-            report_file = report_dir.join("a_Build.xml")
-            assert report_file in report_dir.listdir()
-            content = report_file.open().read()
-            assert 'Site BuildName="my_custom_build - a"' in content
-            assert 'Name="my_custom_site"' in content
-            assert "-my_custom_track" in content
+    with capfd.disabled(), tmpdir.as_cwd():
+        install(
+            "--log-file=cdash_reports",
+            "--log-format=cdash",
+            "--cdash-build=my_custom_build",
+            "--cdash-site=my_custom_site",
+            "--cdash-track=my_custom_track",
+            "pkg-a",
+        )
+        report_dir = tmpdir.join("cdash_reports")
+        assert report_dir in tmpdir.listdir()
+        report_file = report_dir.join("pkg-a_Build.xml")
+        assert report_file in report_dir.listdir()
+        content = report_file.open().read()
+        assert 'Site BuildName="my_custom_build - pkg-a"' in content
+        assert 'Name="my_custom_site"' in content
+        assert "-my_custom_track" in content
 
 
 @pytest.mark.disable_clean_stage_check
 def test_cdash_buildstamp_param(tmpdir, mock_fetch, install_mockery, capfd):
     # capfd interferes with Spack's capture of e.g., Build.xml output
-    with capfd.disabled():
-        with tmpdir.as_cwd():
-            cdash_track = "some_mocked_track"
-            buildstamp_format = "%Y%m%d-%H%M-{0}".format(cdash_track)
-            buildstamp = time.strftime(buildstamp_format, time.localtime(int(time.time())))
-            install(
-                "--log-file=cdash_reports",
-                "--log-format=cdash",
-                "--cdash-buildstamp={0}".format(buildstamp),
-                "a",
-            )
-            report_dir = tmpdir.join("cdash_reports")
-            assert report_dir in tmpdir.listdir()
-            report_file = report_dir.join("a_Build.xml")
-            assert report_file in report_dir.listdir()
-            content = report_file.open().read()
-            assert buildstamp in content
+    with capfd.disabled(), tmpdir.as_cwd():
+        cdash_track = "some_mocked_track"
+        buildstamp_format = "%Y%m%d-%H%M-{0}".format(cdash_track)
+        buildstamp = time.strftime(buildstamp_format, time.localtime(int(time.time())))
+        install(
+            "--log-file=cdash_reports",
+            "--log-format=cdash",
+            "--cdash-buildstamp={0}".format(buildstamp),
+            "pkg-a",
+        )
+        report_dir = tmpdir.join("cdash_reports")
+        assert report_dir in tmpdir.listdir()
+        report_file = report_dir.join("pkg-a_Build.xml")
+        assert report_file in report_dir.listdir()
+        content = report_file.open().read()
+        assert buildstamp in content
 
 
 @pytest.mark.disable_clean_stage_check
@@ -632,38 +629,37 @@ def test_cdash_install_from_spec_json(
     tmpdir, mock_fetch, install_mockery, capfd, mock_packages, mock_archive, config
 ):
     # capfd interferes with Spack's capturing
-    with capfd.disabled():
-        with tmpdir.as_cwd():
-            spec_json_path = str(tmpdir.join("spec.json"))
+    with capfd.disabled(), tmpdir.as_cwd():
+        spec_json_path = str(tmpdir.join("spec.json"))
 
-            pkg_spec = Spec("a")
-            pkg_spec.concretize()
+        pkg_spec = Spec("pkg-a")
+        pkg_spec.concretize()
 
-            with open(spec_json_path, "w") as fd:
-                fd.write(pkg_spec.to_json(hash=ht.dag_hash))
+        with open(spec_json_path, "w") as fd:
+            fd.write(pkg_spec.to_json(hash=ht.dag_hash))
 
-            install(
-                "--log-format=cdash",
-                "--log-file=cdash_reports",
-                "--cdash-build=my_custom_build",
-                "--cdash-site=my_custom_site",
-                "--cdash-track=my_custom_track",
-                "-f",
-                spec_json_path,
-            )
+        install(
+            "--log-format=cdash",
+            "--log-file=cdash_reports",
+            "--cdash-build=my_custom_build",
+            "--cdash-site=my_custom_site",
+            "--cdash-track=my_custom_track",
+            "-f",
+            spec_json_path,
+        )
 
-            report_dir = tmpdir.join("cdash_reports")
-            assert report_dir in tmpdir.listdir()
-            report_file = report_dir.join("a_Configure.xml")
-            assert report_file in report_dir.listdir()
-            content = report_file.open().read()
-            install_command_regex = re.compile(
-                r"<ConfigureCommand>(.+)</ConfigureCommand>", re.MULTILINE | re.DOTALL
-            )
-            m = install_command_regex.search(content)
-            assert m
-            install_command = m.group(1)
-            assert "a@" in install_command
+        report_dir = tmpdir.join("cdash_reports")
+        assert report_dir in tmpdir.listdir()
+        report_file = report_dir.join("pkg-a_Configure.xml")
+        assert report_file in report_dir.listdir()
+        content = report_file.open().read()
+        install_command_regex = re.compile(
+            r"<ConfigureCommand>(.+)</ConfigureCommand>", re.MULTILINE | re.DOTALL
+        )
+        m = install_command_regex.search(content)
+        assert m
+        install_command = m.group(1)
+        assert "pkg-a@" in install_command
 
 
 @pytest.mark.disable_clean_stage_check
@@ -795,15 +791,15 @@ def test_install_no_add_in_env(tmpdir, mock_fetch, install_mockery, mutable_mock
     #                 ^libdwarf
     #         ^mpich
     #     libelf@0.8.10
-    #     a~bvv
-    #         ^b
-    #     a
-    #         ^b
+    #     pkg-a~bvv
+    #         ^pkg-b
+    #     pkg-a
+    #         ^pkg-b
     e = ev.create("test", with_view=False)
     e.add("mpileaks")
     e.add("libelf@0.8.10")  # so env has both root and dep libelf specs
-    e.add("a")
-    e.add("a ~bvv")
+    e.add("pkg-a")
+    e.add("pkg-a ~bvv")
     e.concretize()
     e.write()
     env_specs = e.all_specs()
@@ -814,9 +810,9 @@ def test_install_no_add_in_env(tmpdir, mock_fetch, install_mockery, mutable_mock
 
     # First find and remember some target concrete specs in the environment
     for e_spec in env_specs:
-        if e_spec.satisfies(Spec("a ~bvv")):
+        if e_spec.satisfies(Spec("pkg-a ~bvv")):
             a_spec = e_spec
-        elif e_spec.name == "b":
+        elif e_spec.name == "pkg-b":
             b_spec = e_spec
         elif e_spec.satisfies(Spec("mpi")):
             mpi_spec = e_spec
@@ -839,8 +835,8 @@ def test_install_no_add_in_env(tmpdir, mock_fetch, install_mockery, mutable_mock
         assert "You can add specs to the environment with 'spack add " in inst_out
 
         # Without --add, ensure that two packages "a" get installed
-        inst_out = install("a", output=str)
-        assert len([x for x in e.all_specs() if x.installed and x.name == "a"]) == 2
+        inst_out = install("pkg-a", output=str)
+        assert len([x for x in e.all_specs() if x.installed and x.name == "pkg-a"]) == 2
 
         # Install an unambiguous dependency spec (that already exists as a dep
         # in the environment) and make sure it gets installed (w/ deps),
@@ -873,7 +869,7 @@ def test_install_no_add_in_env(tmpdir, mock_fetch, install_mockery, mutable_mock
         # root of the environment as well as installed.
         assert b_spec not in e.roots()
 
-        install("--add", "b")
+        install("--add", "pkg-b")
 
         assert b_spec in e.roots()
         assert b_spec not in e.uninstalled_specs()
@@ -908,7 +904,7 @@ def test_cdash_auth_token(tmpdir, mock_fetch, install_mockery, monkeypatch, capf
     # capfd interferes with Spack's capturing
     with tmpdir.as_cwd(), capfd.disabled():
         monkeypatch.setenv("SPACK_CDASH_AUTH_TOKEN", "asdf")
-        out = install("-v", "--log-file=cdash_reports", "--log-format=cdash", "a")
+        out = install("-v", "--log-file=cdash_reports", "--log-format=cdash", "pkg-a")
         assert "Using CDash auth token from environment" in out
 
 
@@ -916,26 +912,25 @@ def test_cdash_auth_token(tmpdir, mock_fetch, install_mockery, monkeypatch, capf
 @pytest.mark.disable_clean_stage_check
 def test_cdash_configure_warning(tmpdir, mock_fetch, install_mockery, capfd):
     # capfd interferes with Spack's capturing of e.g., Build.xml output
-    with capfd.disabled():
-        with tmpdir.as_cwd():
-            # Test would fail if install raised an error.
+    with capfd.disabled(), tmpdir.as_cwd():
+        # Test would fail if install raised an error.
 
-            # Ensure that even on non-x86_64 architectures, there are no
-            # dependencies installed
-            spec = spack.spec.Spec("configure-warning").concretized()
-            spec.clear_dependencies()
-            specfile = "./spec.json"
-            with open(specfile, "w") as f:
-                f.write(spec.to_json())
+        # Ensure that even on non-x86_64 architectures, there are no
+        # dependencies installed
+        spec = Spec("configure-warning").concretized()
+        spec.clear_dependencies()
+        specfile = "./spec.json"
+        with open(specfile, "w") as f:
+            f.write(spec.to_json())
 
-            install("--log-file=cdash_reports", "--log-format=cdash", specfile)
-            # Verify Configure.xml exists with expected contents.
-            report_dir = tmpdir.join("cdash_reports")
-            assert report_dir in tmpdir.listdir()
-            report_file = report_dir.join("Configure.xml")
-            assert report_file in report_dir.listdir()
-            content = report_file.open().read()
-            assert "foo: No such file or directory" in content
+        install("--log-file=cdash_reports", "--log-format=cdash", specfile)
+        # Verify Configure.xml exists with expected contents.
+        report_dir = tmpdir.join("cdash_reports")
+        assert report_dir in tmpdir.listdir()
+        report_file = report_dir.join("Configure.xml")
+        assert report_file in report_dir.listdir()
+        content = report_file.open().read()
+        assert "foo: No such file or directory" in content
 
 
 @pytest.mark.not_on_windows("ArchSpec gives test platform debian rather than windows")
@@ -952,7 +947,7 @@ def test_compiler_bootstrap(
     assert CompilerSpec("gcc@=12.0") not in compilers.all_compiler_specs()
 
     # Test succeeds if it does not raise an error
-    install("a%gcc@=12.0")
+    install("pkg-a%gcc@=12.0")
 
 
 @pytest.mark.not_on_windows("Binary mirrors not supported on windows")
@@ -992,8 +987,8 @@ def test_compiler_bootstrap_from_binary_mirror(
     # Now make sure that when the compiler is installed from binary mirror,
     # it also gets configured as a compiler.  Test succeeds if it does not
     # raise an error
-    install("--no-check-signature", "--cache-only", "--only", "dependencies", "b%gcc@=10.2.0")
-    install("--no-cache", "--only", "package", "b%gcc@10.2.0")
+    install("--no-check-signature", "--cache-only", "--only", "dependencies", "pkg-b%gcc@=10.2.0")
+    install("--no-cache", "--only", "package", "pkg-b%gcc@10.2.0")
 
 
 @pytest.mark.not_on_windows("ArchSpec gives test platform debian rather than windows")
@@ -1013,7 +1008,7 @@ def test_compiler_bootstrap_already_installed(
 
     # Test succeeds if it does not raise an error
     install("gcc@=12.0")
-    install("a%gcc@=12.0")
+    install("pkg-a%gcc@=12.0")
 
 
 def test_install_fails_no_args(tmpdir):
@@ -1195,7 +1190,7 @@ def test_report_filename_for_cdash(install_mockery_mutable_config, mock_fetch):
     parser = argparse.ArgumentParser()
     spack.cmd.install.setup_parser(parser)
     args = parser.parse_args(
-        ["--cdash-upload-url", "https://blahblah/submit.php?project=debugging", "a"]
+        ["--cdash-upload-url", "https://blahblah/submit.php?project=debugging", "pkg-a"]
     )
     specs = spack.cmd.install.concrete_specs_from_cli(args, {})
     filename = spack.cmd.install.report_filename(args, specs)
diff --git a/lib/spack/spack/test/cmd/maintainers.py b/lib/spack/spack/test/cmd/maintainers.py
index 5063877a10..23dc3eacb4 100644
--- a/lib/spack/spack/test/cmd/maintainers.py
+++ b/lib/spack/spack/test/cmd/maintainers.py
@@ -133,7 +133,7 @@ def test_maintainers_list_packages(mock_packages, capfd):
 
 
 def test_maintainers_list_fails(mock_packages, capfd):
-    out = maintainers("a", fail_on_error=False)
+    out = maintainers("pkg-a", fail_on_error=False)
     assert not out
     assert maintainers.returncode == 1
 
diff --git a/lib/spack/spack/test/cmd/module.py b/lib/spack/spack/test/cmd/module.py
index a885de79ee..f3ad23c581 100644
--- a/lib/spack/spack/test/cmd/module.py
+++ b/lib/spack/spack/test/cmd/module.py
@@ -11,6 +11,7 @@
 import spack.config
 import spack.main
 import spack.modules
+import spack.spec
 import spack.store
 
 module = spack.main.SpackCommand("module")
@@ -178,8 +179,8 @@ def test_setdefault_command(mutable_database, mutable_config):
         }
     }
     spack.config.set("modules", data)
-    # Install two different versions of a package
-    other_spec, preferred = "a@1.0", "a@2.0"
+    # Install two different versions of pkg-a
+    other_spec, preferred = "pkg-a@1.0", "pkg-a@2.0"
 
     spack.spec.Spec(other_spec).concretized().package.do_install(fake=True)
     spack.spec.Spec(preferred).concretized().package.do_install(fake=True)
diff --git a/lib/spack/spack/test/cmd/pkg.py b/lib/spack/spack/test/cmd/pkg.py
index 56a1f1f786..9677cd5af3 100644
--- a/lib/spack/spack/test/cmd/pkg.py
+++ b/lib/spack/spack/test/cmd/pkg.py
@@ -28,8 +28,8 @@ def install(self, spec, prefix):
         pass
 """
 
-abc = set(("pkg-a", "pkg-b", "pkg-c"))
-abd = set(("pkg-a", "pkg-b", "pkg-d"))
+abc = {"mockpkg-a", "mockpkg-b", "mockpkg-c"}
+abd = {"mockpkg-a", "mockpkg-b", "mockpkg-d"}
 
 
 # Force all tests to use a git repository *in* the mock packages repo.
@@ -53,27 +53,33 @@ def mock_pkg_git_repo(git, tmpdir_factory):
         git("config", "user.name", "Spack Testing")
         git("-c", "commit.gpgsign=false", "commit", "-m", "initial mock repo commit")
 
-        # add commit with pkg-a, pkg-b, pkg-c packages
-        mkdirp("pkg-a", "pkg-b", "pkg-c")
-        with open("pkg-a/package.py", "w") as f:
+        # add commit with mockpkg-a, mockpkg-b, mockpkg-c packages
+        mkdirp("mockpkg-a", "mockpkg-b", "mockpkg-c")
+        with open("mockpkg-a/package.py", "w") as f:
             f.write(pkg_template.format(name="PkgA"))
-        with open("pkg-b/package.py", "w") as f:
+        with open("mockpkg-b/package.py", "w") as f:
             f.write(pkg_template.format(name="PkgB"))
-        with open("pkg-c/package.py", "w") as f:
+        with open("mockpkg-c/package.py", "w") as f:
             f.write(pkg_template.format(name="PkgC"))
-        git("add", "pkg-a", "pkg-b", "pkg-c")
-        git("-c", "commit.gpgsign=false", "commit", "-m", "add pkg-a, pkg-b, pkg-c")
+        git("add", "mockpkg-a", "mockpkg-b", "mockpkg-c")
+        git("-c", "commit.gpgsign=false", "commit", "-m", "add mockpkg-a, mockpkg-b, mockpkg-c")
 
-        # remove pkg-c, add pkg-d
-        with open("pkg-b/package.py", "a") as f:
-            f.write("\n# change pkg-b")
-        git("add", "pkg-b")
-        mkdirp("pkg-d")
-        with open("pkg-d/package.py", "w") as f:
+        # remove mockpkg-c, add mockpkg-d
+        with open("mockpkg-b/package.py", "a") as f:
+            f.write("\n# change mockpkg-b")
+        git("add", "mockpkg-b")
+        mkdirp("mockpkg-d")
+        with open("mockpkg-d/package.py", "w") as f:
             f.write(pkg_template.format(name="PkgD"))
-        git("add", "pkg-d")
-        git("rm", "-rf", "pkg-c")
-        git("-c", "commit.gpgsign=false", "commit", "-m", "change pkg-b, remove pkg-c, add pkg-d")
+        git("add", "mockpkg-d")
+        git("rm", "-rf", "mockpkg-c")
+        git(
+            "-c",
+            "commit.gpgsign=false",
+            "commit",
+            "-m",
+            "change mockpkg-b, remove mockpkg-c, add mockpkg-d",
+        )
 
     with spack.repo.use_repositories(str(repo_path)):
         yield mock_repo_packages
@@ -86,12 +92,11 @@ def mock_pkg_names():
     # Be sure to include virtual packages since packages with stand-alone
     # tests may inherit additional tests from the virtuals they provide,
     # such as packages that implement `mpi`.
-    names = set(
+    return {
         name
         for name in repo.all_package_names(include_virtuals=True)
-        if not name.startswith("pkg-")
-    )
-    return names
+        if not name.startswith("mockpkg-")
+    }
 
 
 def split(output):
@@ -113,17 +118,17 @@ def test_mock_packages_path(mock_packages):
 
 def test_pkg_add(git, mock_pkg_git_repo):
     with working_dir(mock_pkg_git_repo):
-        mkdirp("pkg-e")
-        with open("pkg-e/package.py", "w") as f:
+        mkdirp("mockpkg-e")
+        with open("mockpkg-e/package.py", "w") as f:
             f.write(pkg_template.format(name="PkgE"))
 
-    pkg("add", "pkg-e")
+    pkg("add", "mockpkg-e")
 
     with working_dir(mock_pkg_git_repo):
         try:
-            assert "A  pkg-e/package.py" in git("status", "--short", output=str)
+            assert "A  mockpkg-e/package.py" in git("status", "--short", output=str)
         finally:
-            shutil.rmtree("pkg-e")
+            shutil.rmtree("mockpkg-e")
             # Removing a package mid-run disrupts Spack's caching
             if spack.repo.PATH.repos[0]._fast_package_checker:
                 spack.repo.PATH.repos[0]._fast_package_checker.invalidate()
@@ -138,10 +143,10 @@ def test_pkg_list(mock_pkg_git_repo, mock_pkg_names):
     assert sorted(mock_pkg_names) == sorted(out)
 
     out = split(pkg("list", "HEAD^"))
-    assert sorted(mock_pkg_names.union(["pkg-a", "pkg-b", "pkg-c"])) == sorted(out)
+    assert sorted(mock_pkg_names.union(["mockpkg-a", "mockpkg-b", "mockpkg-c"])) == sorted(out)
 
     out = split(pkg("list", "HEAD"))
-    assert sorted(mock_pkg_names.union(["pkg-a", "pkg-b", "pkg-d"])) == sorted(out)
+    assert sorted(mock_pkg_names.union(["mockpkg-a", "mockpkg-b", "mockpkg-d"])) == sorted(out)
 
     # test with three dots to make sure pkg calls `git merge-base`
     out = split(pkg("list", "HEAD^^..."))
@@ -151,25 +156,25 @@ def test_pkg_list(mock_pkg_git_repo, mock_pkg_names):
 @pytest.mark.not_on_windows("stdout format conflict")
 def test_pkg_diff(mock_pkg_git_repo, mock_pkg_names):
     out = split(pkg("diff", "HEAD^^", "HEAD^"))
-    assert out == ["HEAD^:", "pkg-a", "pkg-b", "pkg-c"]
+    assert out == ["HEAD^:", "mockpkg-a", "mockpkg-b", "mockpkg-c"]
 
     out = split(pkg("diff", "HEAD^^", "HEAD"))
-    assert out == ["HEAD:", "pkg-a", "pkg-b", "pkg-d"]
+    assert out == ["HEAD:", "mockpkg-a", "mockpkg-b", "mockpkg-d"]
 
     out = split(pkg("diff", "HEAD^", "HEAD"))
-    assert out == ["HEAD^:", "pkg-c", "HEAD:", "pkg-d"]
+    assert out == ["HEAD^:", "mockpkg-c", "HEAD:", "mockpkg-d"]
 
 
 @pytest.mark.not_on_windows("stdout format conflict")
 def test_pkg_added(mock_pkg_git_repo):
     out = split(pkg("added", "HEAD^^", "HEAD^"))
-    assert ["pkg-a", "pkg-b", "pkg-c"] == out
+    assert ["mockpkg-a", "mockpkg-b", "mockpkg-c"] == out
 
     out = split(pkg("added", "HEAD^^", "HEAD"))
-    assert ["pkg-a", "pkg-b", "pkg-d"] == out
+    assert ["mockpkg-a", "mockpkg-b", "mockpkg-d"] == out
 
     out = split(pkg("added", "HEAD^", "HEAD"))
-    assert ["pkg-d"] == out
+    assert ["mockpkg-d"] == out
 
     out = split(pkg("added", "HEAD", "HEAD"))
     assert out == []
@@ -184,7 +189,7 @@ def test_pkg_removed(mock_pkg_git_repo):
     assert out == []
 
     out = split(pkg("removed", "HEAD^", "HEAD"))
-    assert out == ["pkg-c"]
+    assert out == ["mockpkg-c"]
 
 
 @pytest.mark.not_on_windows("stdout format conflict")
@@ -196,34 +201,34 @@ def test_pkg_changed(mock_pkg_git_repo):
     assert out == []
 
     out = split(pkg("changed", "--type", "a", "HEAD^^", "HEAD^"))
-    assert out == ["pkg-a", "pkg-b", "pkg-c"]
+    assert out == ["mockpkg-a", "mockpkg-b", "mockpkg-c"]
 
     out = split(pkg("changed", "--type", "r", "HEAD^^", "HEAD^"))
     assert out == []
 
     out = split(pkg("changed", "--type", "ar", "HEAD^^", "HEAD^"))
-    assert out == ["pkg-a", "pkg-b", "pkg-c"]
+    assert out == ["mockpkg-a", "mockpkg-b", "mockpkg-c"]
 
     out = split(pkg("changed", "--type", "arc", "HEAD^^", "HEAD^"))
-    assert out == ["pkg-a", "pkg-b", "pkg-c"]
+    assert out == ["mockpkg-a", "mockpkg-b", "mockpkg-c"]
 
     out = split(pkg("changed", "HEAD^", "HEAD"))
-    assert out == ["pkg-b"]
+    assert out == ["mockpkg-b"]
 
     out = split(pkg("changed", "--type", "c", "HEAD^", "HEAD"))
-    assert out == ["pkg-b"]
+    assert out == ["mockpkg-b"]
 
     out = split(pkg("changed", "--type", "a", "HEAD^", "HEAD"))
-    assert out == ["pkg-d"]
+    assert out == ["mockpkg-d"]
 
     out = split(pkg("changed", "--type", "r", "HEAD^", "HEAD"))
-    assert out == ["pkg-c"]
+    assert out == ["mockpkg-c"]
 
     out = split(pkg("changed", "--type", "ar", "HEAD^", "HEAD"))
-    assert out == ["pkg-c", "pkg-d"]
+    assert out == ["mockpkg-c", "mockpkg-d"]
 
     out = split(pkg("changed", "--type", "arc", "HEAD^", "HEAD"))
-    assert out == ["pkg-b", "pkg-c", "pkg-d"]
+    assert out == ["mockpkg-b", "mockpkg-c", "mockpkg-d"]
 
     # invalid type argument
     with pytest.raises(spack.main.SpackCommandError):
@@ -289,7 +294,7 @@ def test_pkg_canonical_source(mock_packages):
 
 
 def test_pkg_hash(mock_packages):
-    output = pkg("hash", "a", "b").strip().split()
+    output = pkg("hash", "pkg-a", "pkg-b").strip().split()
     assert len(output) == 2 and all(len(elt) == 32 for elt in output)
 
     output = pkg("hash", "multimethod").strip().split()
diff --git a/lib/spack/spack/test/cmd/spec.py b/lib/spack/spack/test/cmd/spec.py
index 66dfce9308..2eb2b13948 100644
--- a/lib/spack/spack/test/cmd/spec.py
+++ b/lib/spack/spack/test/cmd/spec.py
@@ -59,7 +59,7 @@ def test_spec_concretizer_args(mutable_config, mutable_database):
 def test_spec_parse_dependency_variant_value():
     """Verify that we can provide multiple key=value variants to multiple separate
     packages within a spec string."""
-    output = spec("multivalue-variant fee=barbaz ^ a foobar=baz")
+    output = spec("multivalue-variant fee=barbaz ^ pkg-a foobar=baz")
 
     assert "fee=barbaz" in output
     assert "foobar=baz" in output
diff --git a/lib/spack/spack/test/cmd/test.py b/lib/spack/spack/test/cmd/test.py
index 254baa253b..05aab9598f 100644
--- a/lib/spack/spack/test/cmd/test.py
+++ b/lib/spack/spack/test/cmd/test.py
@@ -10,10 +10,14 @@
 
 from llnl.util.filesystem import copy_tree
 
+import spack.cmd.common.arguments
 import spack.cmd.install
+import spack.cmd.test
 import spack.config
+import spack.install_test
 import spack.package_base
 import spack.paths
+import spack.spec
 import spack.store
 from spack.install_test import TestStatus
 from spack.main import SpackCommand
diff --git a/lib/spack/spack/test/concretize.py b/lib/spack/spack/test/concretize.py
index 810a473cde..47fcc639c9 100644
--- a/lib/spack/spack/test/concretize.py
+++ b/lib/spack/spack/test/concretize.py
@@ -23,6 +23,8 @@
 import spack.platforms
 import spack.repo
 import spack.solver.asp
+import spack.store
+import spack.util.file_cache
 import spack.variant as vt
 from spack.concretize import find_spec
 from spack.spec import CompilerSpec, Spec
@@ -369,7 +371,7 @@ def test_compiler_flags_from_compiler_and_dependent(self):
     def test_compiler_flags_differ_identical_compilers(self, mutable_config, clang12_with_flags):
         mutable_config.set("compilers", [clang12_with_flags])
         # Correct arch to use test compiler that has flags
-        spec = Spec("a %clang@12.2.0 platform=test os=fe target=fe")
+        spec = Spec("pkg-a %clang@12.2.0 platform=test os=fe target=fe")
 
         # Get the compiler that matches the spec (
         compiler = spack.compilers.compiler_for_spec("clang@=12.2.0", spec.architecture)
@@ -438,7 +440,7 @@ def test_architecture_deep_inheritance(self, mock_targets, compiler_factory):
                 assert s.architecture.target == spec.architecture.target
 
     def test_compiler_flags_from_user_are_grouped(self):
-        spec = Spec('a%gcc cflags="-O -foo-flag foo-val" platform=test')
+        spec = Spec('pkg-a%gcc cflags="-O -foo-flag foo-val" platform=test')
         spec.concretize()
         cflags = spec.compiler_flags["cflags"]
         assert any(x == "-foo-flag foo-val" for x in cflags)
@@ -546,20 +548,20 @@ def test_concretize_propagate_multivalue_variant(self):
         spec = Spec("multivalue-variant foo==baz,fee")
         spec.concretize()
 
-        assert spec.satisfies("^a foo=baz,fee")
-        assert spec.satisfies("^b foo=baz,fee")
-        assert not spec.satisfies("^a foo=bar")
-        assert not spec.satisfies("^b foo=bar")
+        assert spec.satisfies("^pkg-a foo=baz,fee")
+        assert spec.satisfies("^pkg-b foo=baz,fee")
+        assert not spec.satisfies("^pkg-a foo=bar")
+        assert not spec.satisfies("^pkg-b foo=bar")
 
     def test_no_matching_compiler_specs(self, mock_low_high_config):
         # only relevant when not building compilers as needed
         with spack.concretize.enable_compiler_existence_check():
-            s = Spec("a %gcc@=0.0.0")
+            s = Spec("pkg-a %gcc@=0.0.0")
             with pytest.raises(spack.concretize.UnavailableCompilerVersionError):
                 s.concretize()
 
     def test_no_compilers_for_arch(self):
-        s = Spec("a arch=linux-rhel0-x86_64")
+        s = Spec("pkg-a arch=linux-rhel0-x86_64")
         with pytest.raises(spack.error.SpackError):
             s.concretize()
 
@@ -768,7 +770,7 @@ def test_regression_issue_7941(self):
         # The string representation of a spec containing
         # an explicit multi-valued variant and a dependency
         # might be parsed differently than the originating spec
-        s = Spec("a foobar=bar ^b")
+        s = Spec("pkg-a foobar=bar ^pkg-b")
         t = Spec(str(s))
 
         s.concretize()
@@ -1140,14 +1142,14 @@ def test_conditional_provides_or_depends_on(self):
         [
             # Check that True is treated correctly and attaches test deps
             # to all nodes in the DAG
-            ("a", True, ["a"], []),
-            ("a foobar=bar", True, ["a", "b"], []),
+            ("pkg-a", True, ["pkg-a"], []),
+            ("pkg-a foobar=bar", True, ["pkg-a", "pkg-b"], []),
             # Check that a list of names activates the dependency only for
             # packages in that list
-            ("a foobar=bar", ["a"], ["a"], ["b"]),
-            ("a foobar=bar", ["b"], ["b"], ["a"]),
+            ("pkg-a foobar=bar", ["pkg-a"], ["pkg-a"], ["pkg-b"]),
+            ("pkg-a foobar=bar", ["pkg-b"], ["pkg-b"], ["pkg-a"]),
             # Check that False disregard test dependencies
-            ("a foobar=bar", False, [], ["a", "b"]),
+            ("pkg-a foobar=bar", False, [], ["pkg-a", "pkg-b"]),
         ],
     )
     def test_activating_test_dependencies(self, spec_str, tests_arg, with_dep, without_dep):
@@ -1205,7 +1207,7 @@ def test_custom_compiler_version(self, mutable_config, compiler_factory):
         mutable_config.set(
             "compilers", [compiler_factory(spec="gcc@10foo", operating_system="redhat6")]
         )
-        s = Spec("a %gcc@10foo os=redhat6").concretized()
+        s = Spec("pkg-a %gcc@10foo os=redhat6").concretized()
         assert "%gcc@10foo" in s
 
     def test_all_patches_applied(self):
@@ -1330,10 +1332,10 @@ def test_reuse_installed_packages_when_package_def_changes(
     @pytest.mark.only_clingo("Use case not supported by the original concretizer")
     def test_reuse_with_flags(self, mutable_database, mutable_config):
         spack.config.set("concretizer:reuse", True)
-        spec = Spec("a cflags=-g cxxflags=-g").concretized()
+        spec = Spec("pkg-a cflags=-g cxxflags=-g").concretized()
         spack.store.STORE.db.add(spec, None)
 
-        testspec = Spec("a cflags=-g")
+        testspec = Spec("pkg-a cflags=-g")
         testspec.concretize()
         assert testspec == spec
 
@@ -1674,31 +1676,31 @@ def test_reuse_with_unknown_namespace_dont_raise(
         self, temporary_store, mock_custom_repository
     ):
         with spack.repo.use_repositories(mock_custom_repository, override=False):
-            s = Spec("c").concretized()
+            s = Spec("pkg-c").concretized()
             assert s.namespace != "builtin.mock"
             s.package.do_install(fake=True, explicit=True)
 
         with spack.config.override("concretizer:reuse", True):
-            s = Spec("c").concretized()
+            s = Spec("pkg-c").concretized()
         assert s.namespace == "builtin.mock"
 
     @pytest.mark.regression("28259")
     def test_reuse_with_unknown_package_dont_raise(self, tmpdir, temporary_store, monkeypatch):
         builder = spack.repo.MockRepositoryBuilder(tmpdir.mkdir("mock.repo"), namespace="myrepo")
-        builder.add_package("c")
+        builder.add_package("pkg-c")
         with spack.repo.use_repositories(builder.root, override=False):
-            s = Spec("c").concretized()
+            s = Spec("pkg-c").concretized()
             assert s.namespace == "myrepo"
             s.package.do_install(fake=True, explicit=True)
 
-        del sys.modules["spack.pkg.myrepo.c"]
+        del sys.modules["spack.pkg.myrepo.pkg-c"]
         del sys.modules["spack.pkg.myrepo"]
-        builder.remove("c")
+        builder.remove("pkg-c")
         with spack.repo.use_repositories(builder.root, override=False) as repos:
             # TODO (INJECT CONFIGURATION): unclear why the cache needs to be invalidated explicitly
             repos.repos[0]._pkg_checker.invalidate()
             with spack.config.override("concretizer:reuse", True):
-                s = Spec("c").concretized()
+                s = Spec("pkg-c").concretized()
             assert s.namespace == "builtin.mock"
 
     @pytest.mark.parametrize(
@@ -1810,20 +1812,20 @@ def test_misleading_error_message_on_version(self, mutable_database):
     @pytest.mark.only_clingo("Use case not supported by the original concretizer")
     def test_version_weight_and_provenance(self):
         """Test package preferences during coconcretization."""
-        reusable_specs = [Spec(spec_str).concretized() for spec_str in ("b@0.9", "b@1.0")]
-        root_spec = Spec("a foobar=bar")
+        reusable_specs = [Spec(spec_str).concretized() for spec_str in ("pkg-b@0.9", "pkg-b@1.0")]
+        root_spec = Spec("pkg-a foobar=bar")
 
         with spack.config.override("concretizer:reuse", True):
             solver = spack.solver.asp.Solver()
             setup = spack.solver.asp.SpackSolverSetup()
             result, _, _ = solver.driver.solve(setup, [root_spec], reuse=reusable_specs)
-            # The result here should have a single spec to build ('a')
-            # and it should be using b@1.0 with a version badness of 2
+            # The result here should have a single spec to build ('pkg-a')
+            # and it should be using pkg-b@1.0 with a version badness of 2
             # The provenance is:
-            # version_declared("b","1.0",0,"package_py").
-            # version_declared("b","0.9",1,"package_py").
-            # version_declared("b","1.0",2,"installed").
-            # version_declared("b","0.9",3,"installed").
+            # version_declared("pkg-b","1.0",0,"package_py").
+            # version_declared("pkg-b","0.9",1,"package_py").
+            # version_declared("pkg-b","1.0",2,"installed").
+            # version_declared("pkg-b","0.9",3,"installed").
             #
             # Depending on the target, it may also use gnuconfig
             result_spec = result.specs[0]
@@ -1836,12 +1838,12 @@ def test_version_weight_and_provenance(self):
 
             for criterion in criteria:
                 assert criterion in result.criteria
-            assert result_spec.satisfies("^b@1.0")
+            assert result_spec.satisfies("^pkg-b@1.0")
 
     @pytest.mark.regression("31169")
     @pytest.mark.only_clingo("Use case not supported by the original concretizer")
     def test_not_reusing_incompatible_os_or_compiler(self):
-        root_spec = Spec("b")
+        root_spec = Spec("pkg-b")
         s = root_spec.concretized()
         wrong_compiler, wrong_os = s.copy(), s.copy()
         wrong_compiler.compiler = spack.spec.CompilerSpec("gcc@12.1.0")
@@ -2096,7 +2098,7 @@ def test_external_python_extension_find_unified_python(self):
         "specs",
         [
             ["mpileaks^ callpath ^dyninst@8.1.1:8 ^mpich2@1.3:1"],
-            ["multivalue-variant ^a@2:2"],
+            ["multivalue-variant ^pkg-a@2:2"],
             ["v1-consumer ^conditional-provider@1:1 +disable-v1"],
         ],
     )
@@ -2146,7 +2148,7 @@ def test_compiler_match_constraints_when_selected(self):
             },
         ]
         spack.config.set("compilers", compiler_configuration)
-        s = Spec("a %gcc@:11").concretized()
+        s = Spec("pkg-a %gcc@:11").concretized()
         assert s.compiler.version == ver("=11.1.0"), s
 
     @pytest.mark.regression("36339")
@@ -2167,7 +2169,7 @@ def test_compiler_with_custom_non_numeric_version(self, mock_executable):
             }
         ]
         spack.config.set("compilers", compiler_configuration)
-        s = Spec("a %gcc@foo").concretized()
+        s = Spec("pkg-a %gcc@foo").concretized()
         assert s.compiler.version == ver("=foo")
 
     @pytest.mark.regression("36628")
@@ -2193,7 +2195,7 @@ def test_concretization_with_compilers_supporting_target_any(self):
         ]
 
         with spack.config.override("compilers", compiler_configuration):
-            s = spack.spec.Spec("a").concretized()
+            s = Spec("pkg-a").concretized()
         assert s.satisfies("%gcc@12.1.0")
 
     @pytest.mark.parametrize("spec_str", ["mpileaks", "mpileaks ^mpich"])
@@ -2228,7 +2230,7 @@ def test_dont_define_new_version_from_input_if_checksum_required(self, working_e
         with pytest.raises(spack.error.UnsatisfiableSpecError):
             # normally spack concretizes to @=3.0 if it's not defined in package.py, except
             # when checksums are required
-            Spec("a@=3.0").concretized()
+            Spec("pkg-a@=3.0").concretized()
 
     @pytest.mark.regression("39570")
     @pytest.mark.db
@@ -2453,7 +2455,9 @@ def test_drop_moving_targets(v_str, v_opts, checksummed):
 class TestConcreteSpecsByHash:
     """Tests the container of concrete specs"""
 
-    @pytest.mark.parametrize("input_specs", [["a"], ["a foobar=bar", "b"], ["a foobar=baz", "b"]])
+    @pytest.mark.parametrize(
+        "input_specs", [["pkg-a"], ["pkg-a foobar=bar", "pkg-b"], ["pkg-a foobar=baz", "pkg-b"]]
+    )
     def test_adding_specs(self, input_specs, default_mock_concretization):
         """Tests that concrete specs in the container are equivalent, but stored as different
         objects in memory.
diff --git a/lib/spack/spack/test/concretize_preferences.py b/lib/spack/spack/test/concretize_preferences.py
index 295062faea..c40a415405 100644
--- a/lib/spack/spack/test/concretize_preferences.py
+++ b/lib/spack/spack/test/concretize_preferences.py
@@ -512,5 +512,5 @@ def test_default_preference_variant_different_type_does_not_error(self):
         packages.yaml doesn't fail with an error.
         """
         with spack.config.override("packages:all", {"variants": "+foo"}):
-            s = Spec("a").concretized()
+            s = Spec("pkg-a").concretized()
             assert s.satisfies("foo=bar")
diff --git a/lib/spack/spack/test/config.py b/lib/spack/spack/test/config.py
index 2453172bec..c07b0aa5a6 100644
--- a/lib/spack/spack/test/config.py
+++ b/lib/spack/spack/test/config.py
@@ -1176,13 +1176,13 @@ def test_license_dir_config(mutable_config, mock_packages):
     expected_dir = spack.paths.default_license_dir
     assert spack.config.get("config:license_dir") == expected_dir
     assert spack.package_base.PackageBase.global_license_dir == expected_dir
-    assert spack.repo.PATH.get_pkg_class("a").global_license_dir == expected_dir
+    assert spack.repo.PATH.get_pkg_class("pkg-a").global_license_dir == expected_dir
 
     rel_path = os.path.join(os.path.sep, "foo", "bar", "baz")
     spack.config.set("config:license_dir", rel_path)
     assert spack.config.get("config:license_dir") == rel_path
     assert spack.package_base.PackageBase.global_license_dir == rel_path
-    assert spack.repo.PATH.get_pkg_class("a").global_license_dir == rel_path
+    assert spack.repo.PATH.get_pkg_class("pkg-a").global_license_dir == rel_path
 
 
 @pytest.mark.regression("22547")
diff --git a/lib/spack/spack/test/conftest.py b/lib/spack/spack/test/conftest.py
index 2bde1430fd..645c279444 100644
--- a/lib/spack/spack/test/conftest.py
+++ b/lib/spack/spack/test/conftest.py
@@ -597,7 +597,7 @@ def mutable_mock_repo(mock_repo_path, request):
 def mock_custom_repository(tmpdir, mutable_mock_repo):
     """Create a custom repository with a single package "c" and return its path."""
     builder = spack.repo.MockRepositoryBuilder(tmpdir.mkdir("myrepo"))
-    builder.add_package("c")
+    builder.add_package("pkg-c")
     return builder.root
 
 
diff --git a/lib/spack/spack/test/database.py b/lib/spack/spack/test/database.py
index ee3e5da81e..b17eee7d37 100644
--- a/lib/spack/spack/test/database.py
+++ b/lib/spack/spack/test/database.py
@@ -69,7 +69,7 @@ def test_spec_installed_upstream(
 
     # a known installed spec should say that it's installed
     with spack.repo.use_repositories(mock_custom_repository):
-        spec = spack.spec.Spec("c").concretized()
+        spec = spack.spec.Spec("pkg-c").concretized()
         assert not spec.installed
         assert not spec.installed_upstream
 
@@ -813,7 +813,7 @@ def test_query_virtual_spec(database):
 
 def test_failed_spec_path_error(database):
     """Ensure spec not concrete check is covered."""
-    s = spack.spec.Spec("a")
+    s = spack.spec.Spec("pkg-a")
     with pytest.raises(AssertionError, match="concrete spec required"):
         spack.store.STORE.failure_tracker.mark(s)
 
@@ -828,7 +828,7 @@ def _is(self, spec):
     # Pretend the spec has been failure locked
     monkeypatch.setattr(spack.database.FailureTracker, "lock_taken", _is)
 
-    s = spack.spec.Spec("a").concretized()
+    s = spack.spec.Spec("pkg-a").concretized()
     spack.store.STORE.failure_tracker.clear(s)
     out = capfd.readouterr()[0]
     assert "Retaining failure marking" in out
@@ -846,7 +846,7 @@ def _is(self, spec):
     # Ensure raise OSError when try to remove the non-existent marking
     monkeypatch.setattr(spack.database.FailureTracker, "persistent_mark", _is)
 
-    s = default_mock_concretization("a")
+    s = spack.spec.Spec("pkg-a").concretized()
     spack.store.STORE.failure_tracker.clear(s, force=True)
     out = capfd.readouterr()[1]
     assert "Removing failure marking despite lock" in out
@@ -860,15 +860,16 @@ def test_mark_failed(default_mock_concretization, mutable_database, monkeypatch,
     def _raise_exc(lock):
         raise lk.LockTimeoutError("write", "/mock-lock", 1.234, 10)
 
-    # Ensure attempt to acquire write lock on the mark raises the exception
-    monkeypatch.setattr(lk.Lock, "acquire_write", _raise_exc)
-
     with tmpdir.as_cwd():
-        s = default_mock_concretization("a")
+        s = spack.spec.Spec("pkg-a").concretized()
+
+        # Ensure attempt to acquire write lock on the mark raises the exception
+        monkeypatch.setattr(lk.Lock, "acquire_write", _raise_exc)
+
         spack.store.STORE.failure_tracker.mark(s)
 
         out = str(capsys.readouterr()[1])
-        assert "Unable to mark a as failed" in out
+        assert "Unable to mark pkg-a as failed" in out
 
     spack.store.STORE.failure_tracker.clear_all()
 
@@ -877,7 +878,7 @@ def _raise_exc(lock):
 def test_prefix_failed(default_mock_concretization, mutable_database, monkeypatch):
     """Add coverage to failed operation."""
 
-    s = default_mock_concretization("a")
+    s = spack.spec.Spec("pkg-a").concretized()
 
     # Confirm the spec is not already marked as failed
     assert not spack.store.STORE.failure_tracker.has_failed(s)
@@ -901,7 +902,7 @@ def test_prefix_write_lock_error(default_mock_concretization, mutable_database,
     def _raise(db, spec):
         raise lk.LockError("Mock lock error")
 
-    s = default_mock_concretization("a")
+    s = spack.spec.Spec("pkg-a").concretized()
 
     # Ensure subsequent lock operations fail
     monkeypatch.setattr(lk.Lock, "acquire_write", _raise)
diff --git a/lib/spack/spack/test/directives.py b/lib/spack/spack/test/directives.py
index 677eb043a9..21a2a25c46 100644
--- a/lib/spack/spack/test/directives.py
+++ b/lib/spack/spack/test/directives.py
@@ -30,7 +30,7 @@ def test_true_directives_exist(mock_packages):
 
     assert cls.dependencies
     assert spack.spec.Spec() in cls.dependencies["extendee"]
-    assert spack.spec.Spec() in cls.dependencies["b"]
+    assert spack.spec.Spec() in cls.dependencies["pkg-b"]
 
     assert cls.resources
     assert spack.spec.Spec() in cls.resources
@@ -43,7 +43,7 @@ def test_constraints_from_context(mock_packages):
     pkg_cls = spack.repo.PATH.get_pkg_class("with-constraint-met")
 
     assert pkg_cls.dependencies
-    assert spack.spec.Spec("@1.0") in pkg_cls.dependencies["b"]
+    assert spack.spec.Spec("@1.0") in pkg_cls.dependencies["pkg-b"]
 
     assert pkg_cls.conflicts
     assert (spack.spec.Spec("+foo@1.0"), None) in pkg_cls.conflicts["%gcc"]
@@ -54,7 +54,7 @@ def test_constraints_from_context_are_merged(mock_packages):
     pkg_cls = spack.repo.PATH.get_pkg_class("with-constraint-met")
 
     assert pkg_cls.dependencies
-    assert spack.spec.Spec("@0.14:15 ^b@3.8:4.0") in pkg_cls.dependencies["c"]
+    assert spack.spec.Spec("@0.14:15 ^pkg-b@3.8:4.0") in pkg_cls.dependencies["pkg-c"]
 
 
 @pytest.mark.regression("27754")
@@ -68,7 +68,7 @@ def test_extends_spec(config, mock_packages):
 
 @pytest.mark.regression("34368")
 def test_error_on_anonymous_dependency(config, mock_packages):
-    pkg = spack.repo.PATH.get_pkg_class("a")
+    pkg = spack.repo.PATH.get_pkg_class("pkg-a")
     with pytest.raises(spack.directives.DependencyError):
         spack.directives._depends_on(pkg, "@4.5")
 
diff --git a/lib/spack/spack/test/env.py b/lib/spack/spack/test/env.py
index 21c59488d1..ad8fbe4041 100644
--- a/lib/spack/spack/test/env.py
+++ b/lib/spack/spack/test/env.py
@@ -377,10 +377,10 @@ def test_can_add_specs_to_environment_without_specs_attribute(tmp_path, mock_pac
     """
     )
     env = ev.Environment(tmp_path)
-    env.add("a")
+    env.add("pkg-a")
 
     assert len(env.user_specs) == 1
-    assert env.manifest.pristine_yaml_content["spack"]["specs"] == ["a"]
+    assert env.manifest.pristine_yaml_content["spack"]["specs"] == ["pkg-a"]
 
 
 @pytest.mark.parametrize(
@@ -578,7 +578,7 @@ def test_conflicts_with_packages_that_are_not_dependencies(
 spack:
   specs:
   - {spec_str}
-  - b
+  - pkg-b
   concretizer:
     unify: true
 """
@@ -706,7 +706,7 @@ def test_variant_propagation_with_unify_false(tmp_path, mock_packages, config):
     spack:
       specs:
       - parent-foo ++foo
-      - c
+      - pkg-c
       concretizer:
         unify: false
     """
@@ -791,10 +791,10 @@ def test_deconcretize_then_concretize_does_not_error(mutable_mock_env_path, mock
         """spack:
       specs:
       # These two specs concretize to the same hash
-      - c
-      - c@1.0
+      - pkg-c
+      - pkg-c@1.0
       # Spec used to trigger the bug
-      - a
+      - pkg-a
       concretizer:
         unify: true
     """
@@ -802,8 +802,8 @@ def test_deconcretize_then_concretize_does_not_error(mutable_mock_env_path, mock
     e = ev.Environment(mutable_mock_env_path)
     with e:
         e.concretize()
-        e.deconcretize(spack.spec.Spec("a"), concrete=False)
+        e.deconcretize(spack.spec.Spec("pkg-a"), concrete=False)
         e.concretize()
     assert len(e.concrete_roots()) == 3
-    all_root_hashes = set(x.dag_hash() for x in e.concrete_roots())
+    all_root_hashes = {x.dag_hash() for x in e.concrete_roots()}
     assert len(all_root_hashes) == 2
diff --git a/lib/spack/spack/test/installer.py b/lib/spack/spack/test/installer.py
index 13a36830cd..3dcc159765 100644
--- a/lib/spack/spack/test/installer.py
+++ b/lib/spack/spack/test/installer.py
@@ -132,7 +132,7 @@ def test_hms(sec, result):
 
 def test_get_dependent_ids(install_mockery, mock_packages):
     # Concretize the parent package, which handle dependency too
-    spec = spack.spec.Spec("a")
+    spec = spack.spec.Spec("pkg-a")
     spec.concretize()
     assert spec.concrete
 
@@ -223,11 +223,11 @@ def _spec(spec, unsigned=False, mirrors_for_spec=None):
     # Skip database updates
     monkeypatch.setattr(spack.database.Database, "add", _noop)
 
-    spec = spack.spec.Spec("a").concretized()
+    spec = spack.spec.Spec("pkg-a").concretized()
     assert inst._process_binary_cache_tarball(spec.package, explicit=False, unsigned=False)
 
     out = capfd.readouterr()[0]
-    assert "Extracting a" in out
+    assert "Extracting pkg-a" in out
     assert "from binary cache" in out
 
 
@@ -278,7 +278,7 @@ def test_installer_prune_built_build_deps(install_mockery, monkeypatch, tmpdir):
 
     @property
     def _mock_installed(self):
-        return self.name in ["c"]
+        return self.name == "pkg-c"
 
     # Mock the installed property to say that (b) is installed
     monkeypatch.setattr(spack.spec.Spec, "installed", _mock_installed)
@@ -286,24 +286,25 @@ def _mock_installed(self):
     # Create mock repository with packages (a), (b), (c), (d), and (e)
     builder = spack.repo.MockRepositoryBuilder(tmpdir.mkdir("mock-repo"))
 
-    builder.add_package("a", dependencies=[("b", "build", None), ("c", "build", None)])
-    builder.add_package("b", dependencies=[("d", "build", None)])
+    builder.add_package("pkg-a", dependencies=[("pkg-b", "build", None), ("pkg-c", "build", None)])
+    builder.add_package("pkg-b", dependencies=[("pkg-d", "build", None)])
     builder.add_package(
-        "c", dependencies=[("d", "build", None), ("e", "all", None), ("f", "build", None)]
+        "pkg-c",
+        dependencies=[("pkg-d", "build", None), ("pkg-e", "all", None), ("pkg-f", "build", None)],
     )
-    builder.add_package("d")
-    builder.add_package("e")
-    builder.add_package("f")
+    builder.add_package("pkg-d")
+    builder.add_package("pkg-e")
+    builder.add_package("pkg-f")
 
     with spack.repo.use_repositories(builder.root):
-        const_arg = installer_args(["a"], {})
+        const_arg = installer_args(["pkg-a"], {})
         installer = create_installer(const_arg)
 
         installer._init_queue()
 
         # Assert that (c) is not in the build_pq
-        result = set([task.pkg_id[0] for _, task in installer.build_pq])
-        expected = set(["a", "b", "c", "d", "e"])
+        result = {task.pkg_id[:5] for _, task in installer.build_pq}
+        expected = {"pkg-a", "pkg-b", "pkg-c", "pkg-d", "pkg-e"}
         assert result == expected
 
 
@@ -418,8 +419,7 @@ def test_ensure_locked_have(install_mockery, tmpdir, capsys):
 
 @pytest.mark.parametrize("lock_type,reads,writes", [("read", 1, 0), ("write", 0, 1)])
 def test_ensure_locked_new_lock(install_mockery, tmpdir, lock_type, reads, writes):
-    pkg_id = "a"
-    const_arg = installer_args([pkg_id], {})
+    const_arg = installer_args(["pkg-a"], {})
     installer = create_installer(const_arg)
     spec = installer.build_requests[0].pkg.spec
     with tmpdir.as_cwd():
@@ -438,8 +438,7 @@ def _pl(db, spec, timeout):
         lock.default_timeout = 1e-9 if timeout is None else None
         return lock
 
-    pkg_id = "a"
-    const_arg = installer_args([pkg_id], {})
+    const_arg = installer_args(["pkg-a"], {})
     installer = create_installer(const_arg)
     spec = installer.build_requests[0].pkg.spec
 
@@ -496,7 +495,7 @@ def test_packages_needed_to_bootstrap_compiler_packages(install_mockery, monkeyp
     spec.concretize()
 
     def _conc_spec(compiler):
-        return spack.spec.Spec("a").concretized()
+        return spack.spec.Spec("pkg-a").concretized()
 
     # Ensure we can get past functions that are precluding obtaining
     # packages.
@@ -604,7 +603,7 @@ def test_clear_failures_success(tmpdir):
     """Test the clear_failures happy path."""
     failures = spack.database.FailureTracker(str(tmpdir), default_timeout=0.1)
 
-    spec = spack.spec.Spec("a")
+    spec = spack.spec.Spec("pkg-a")
     spec._mark_concrete()
 
     # Set up a test prefix failure lock
@@ -630,7 +629,7 @@ def test_clear_failures_success(tmpdir):
 def test_clear_failures_errs(tmpdir, capsys):
     """Test the clear_failures exception paths."""
     failures = spack.database.FailureTracker(str(tmpdir), default_timeout=0.1)
-    spec = spack.spec.Spec("a")
+    spec = spack.spec.Spec("pkg-a")
     spec._mark_concrete()
     failures.mark(spec)
 
@@ -692,11 +691,11 @@ def test_check_deps_status_install_failure(install_mockery):
     """Tests that checking the dependency status on a request to install
     'a' fails, if we mark the dependency as failed.
     """
-    s = spack.spec.Spec("a").concretized()
+    s = spack.spec.Spec("pkg-a").concretized()
     for dep in s.traverse(root=False):
         spack.store.STORE.failure_tracker.mark(dep)
 
-    const_arg = installer_args(["a"], {})
+    const_arg = installer_args(["pkg-a"], {})
     installer = create_installer(const_arg)
     request = installer.build_requests[0]
 
@@ -705,7 +704,7 @@ def test_check_deps_status_install_failure(install_mockery):
 
 
 def test_check_deps_status_write_locked(install_mockery, monkeypatch):
-    const_arg = installer_args(["a"], {})
+    const_arg = installer_args(["pkg-a"], {})
     installer = create_installer(const_arg)
     request = installer.build_requests[0]
 
@@ -717,7 +716,7 @@ def test_check_deps_status_write_locked(install_mockery, monkeypatch):
 
 
 def test_check_deps_status_external(install_mockery, monkeypatch):
-    const_arg = installer_args(["a"], {})
+    const_arg = installer_args(["pkg-a"], {})
     installer = create_installer(const_arg)
     request = installer.build_requests[0]
 
@@ -730,7 +729,7 @@ def test_check_deps_status_external(install_mockery, monkeypatch):
 
 
 def test_check_deps_status_upstream(install_mockery, monkeypatch):
-    const_arg = installer_args(["a"], {})
+    const_arg = installer_args(["pkg-a"], {})
     installer = create_installer(const_arg)
     request = installer.build_requests[0]
 
@@ -807,7 +806,7 @@ def test_install_task_add_compiler(install_mockery, monkeypatch, capfd):
     def _add(_compilers):
         tty.msg(config_msg)
 
-    const_arg = installer_args(["a"], {})
+    const_arg = installer_args(["pkg-a"], {})
     installer = create_installer(const_arg)
     task = create_build_task(installer.build_requests[0].pkg)
     task.compiler = True
@@ -845,7 +844,7 @@ def test_release_lock_write_n_exception(install_mockery, tmpdir, capsys):
 @pytest.mark.parametrize("installed", [True, False])
 def test_push_task_skip_processed(install_mockery, installed):
     """Test to ensure skip re-queueing a processed package."""
-    const_arg = installer_args(["a"], {})
+    const_arg = installer_args(["pkg-a"], {})
     installer = create_installer(const_arg)
     assert len(list(installer.build_tasks)) == 0
 
@@ -863,7 +862,7 @@ def test_push_task_skip_processed(install_mockery, installed):
 
 def test_requeue_task(install_mockery, capfd):
     """Test to ensure cover _requeue_task."""
-    const_arg = installer_args(["a"], {})
+    const_arg = installer_args(["pkg-a"], {})
     installer = create_installer(const_arg)
     task = create_build_task(installer.build_requests[0].pkg)
 
@@ -881,7 +880,7 @@ def test_requeue_task(install_mockery, capfd):
     assert qtask.attempts == task.attempts + 1
 
     out = capfd.readouterr()[1]
-    assert "Installing a" in out
+    assert "Installing pkg-a" in out
     assert " in progress by another process" in out
 
 
@@ -894,17 +893,17 @@ def _mktask(pkg):
     def _rmtask(installer, pkg_id):
         raise RuntimeError("Raise an exception to test except path")
 
-    const_arg = installer_args(["a"], {})
+    const_arg = installer_args(["pkg-a"], {})
     installer = create_installer(const_arg)
     spec = installer.build_requests[0].pkg.spec
 
     # Cover task removal happy path
-    installer.build_tasks["a"] = _mktask(spec.package)
+    installer.build_tasks["pkg-a"] = _mktask(spec.package)
     installer._cleanup_all_tasks()
     assert len(installer.build_tasks) == 0
 
     # Cover task removal exception path
-    installer.build_tasks["a"] = _mktask(spec.package)
+    installer.build_tasks["pkg-a"] = _mktask(spec.package)
     monkeypatch.setattr(inst.PackageInstaller, "_remove_task", _rmtask)
     installer._cleanup_all_tasks()
     assert len(installer.build_tasks) == 1
@@ -998,7 +997,7 @@ def test_install_uninstalled_deps(install_mockery, monkeypatch, capsys):
 
 def test_install_failed(install_mockery, monkeypatch, capsys):
     """Test install with failed install."""
-    const_arg = installer_args(["b"], {})
+    const_arg = installer_args(["pkg-b"], {})
     installer = create_installer(const_arg)
 
     # Make sure the package is identified as failed
@@ -1014,7 +1013,7 @@ def test_install_failed(install_mockery, monkeypatch, capsys):
 
 def test_install_failed_not_fast(install_mockery, monkeypatch, capsys):
     """Test install with failed install."""
-    const_arg = installer_args(["a"], {"fail_fast": False})
+    const_arg = installer_args(["pkg-a"], {"fail_fast": False})
     installer = create_installer(const_arg)
 
     # Make sure the package is identified as failed
@@ -1025,12 +1024,12 @@ def test_install_failed_not_fast(install_mockery, monkeypatch, capsys):
 
     out = str(capsys.readouterr())
     assert "failed to install" in out
-    assert "Skipping build of a" in out
+    assert "Skipping build of pkg-a" in out
 
 
 def test_install_fail_on_interrupt(install_mockery, monkeypatch):
     """Test ctrl-c interrupted install."""
-    spec_name = "a"
+    spec_name = "pkg-a"
     err_msg = "mock keyboard interrupt for {0}".format(spec_name)
 
     def _interrupt(installer, task, install_status, **kwargs):
@@ -1048,13 +1047,13 @@ def _interrupt(installer, task, install_status, **kwargs):
     with pytest.raises(KeyboardInterrupt, match=err_msg):
         installer.install()
 
-    assert "b" in installer.installed  # ensure dependency of a is 'installed'
+    assert "pkg-b" in installer.installed  # ensure dependency of pkg-a is 'installed'
     assert spec_name not in installer.installed
 
 
 def test_install_fail_single(install_mockery, monkeypatch):
     """Test expected results for failure of single package."""
-    spec_name = "a"
+    spec_name = "pkg-a"
     err_msg = "mock internal package build error for {0}".format(spec_name)
 
     class MyBuildException(Exception):
@@ -1075,13 +1074,13 @@ def _install(installer, task, install_status, **kwargs):
     with pytest.raises(MyBuildException, match=err_msg):
         installer.install()
 
-    assert "b" in installer.installed  # ensure dependency of a is 'installed'
+    assert "pkg-b" in installer.installed  # ensure dependency of a is 'installed'
     assert spec_name not in installer.installed
 
 
 def test_install_fail_multi(install_mockery, monkeypatch):
     """Test expected results for failure of multiple packages."""
-    spec_name = "c"
+    spec_name = "pkg-c"
     err_msg = "mock internal package build error"
 
     class MyBuildException(Exception):
@@ -1093,7 +1092,7 @@ def _install(installer, task, install_status, **kwargs):
         else:
             installer.installed.add(task.pkg.name)
 
-    const_arg = installer_args([spec_name, "a"], {})
+    const_arg = installer_args([spec_name, "pkg-a"], {})
     installer = create_installer(const_arg)
 
     # Raise a KeyboardInterrupt error to trigger early termination
@@ -1102,14 +1101,14 @@ def _install(installer, task, install_status, **kwargs):
     with pytest.raises(inst.InstallError, match="Installation request failed"):
         installer.install()
 
-    assert "a" in installer.installed  # ensure the the second spec installed
+    assert "pkg-a" in installer.installed  # ensure the the second spec installed
     assert spec_name not in installer.installed
 
 
 def test_install_fail_fast_on_detect(install_mockery, monkeypatch, capsys):
     """Test fail_fast install when an install failure is detected."""
-    const_arg = installer_args(["b"], {"fail_fast": False})
-    const_arg.extend(installer_args(["c"], {"fail_fast": True}))
+    const_arg = installer_args(["pkg-b"], {"fail_fast": False})
+    const_arg.extend(installer_args(["pkg-c"], {"fail_fast": True}))
     installer = create_installer(const_arg)
     pkg_ids = [inst.package_id(spec.package) for spec, _ in const_arg]
 
@@ -1139,7 +1138,7 @@ def _test_install_fail_fast_on_except_patch(installer, **kwargs):
 @pytest.mark.disable_clean_stage_check
 def test_install_fail_fast_on_except(install_mockery, monkeypatch, capsys):
     """Test fail_fast install when an install failure results from an error."""
-    const_arg = installer_args(["a"], {"fail_fast": True})
+    const_arg = installer_args(["pkg-a"], {"fail_fast": True})
     installer = create_installer(const_arg)
 
     # Raise a non-KeyboardInterrupt exception to trigger fast failure.
@@ -1154,7 +1153,7 @@ def test_install_fail_fast_on_except(install_mockery, monkeypatch, capsys):
         installer.install()
 
     out = str(capsys.readouterr())
-    assert "Skipping build of a" in out
+    assert "Skipping build of pkg-a" in out
 
 
 def test_install_lock_failures(install_mockery, monkeypatch, capfd):
@@ -1163,7 +1162,7 @@ def test_install_lock_failures(install_mockery, monkeypatch, capfd):
     def _requeued(installer, task, install_status):
         tty.msg("requeued {0}".format(task.pkg.spec.name))
 
-    const_arg = installer_args(["b"], {})
+    const_arg = installer_args(["pkg-b"], {})
     installer = create_installer(const_arg)
 
     # Ensure never acquire a lock
@@ -1183,7 +1182,7 @@ def _requeued(installer, task, install_status):
 
 def test_install_lock_installed_requeue(install_mockery, monkeypatch, capfd):
     """Cover basic install handling for installed package."""
-    const_arg = installer_args(["b"], {})
+    const_arg = installer_args(["pkg-b"], {})
     b, _ = const_arg[0]
     installer = create_installer(const_arg)
     b_pkg_id = inst.package_id(b.package)
@@ -1239,7 +1238,7 @@ def _requeued(installer, task, install_status):
     # Ensure don't continually requeue the task
     monkeypatch.setattr(inst.PackageInstaller, "_requeue_task", _requeued)
 
-    const_arg = installer_args(["b"], {})
+    const_arg = installer_args(["pkg-b"], {})
     installer = create_installer(const_arg)
 
     with pytest.raises(inst.InstallError, match="request failed"):
@@ -1255,7 +1254,7 @@ def _requeued(installer, task, install_status):
 
 def test_install_skip_patch(install_mockery, mock_fetch):
     """Test the path skip_patch install path."""
-    spec_name = "b"
+    spec_name = "pkg-b"
     const_arg = installer_args([spec_name], {"fake": False, "skip_patch": True})
     installer = create_installer(const_arg)
 
@@ -1282,7 +1281,7 @@ def test_overwrite_install_backup_success(temporary_store, config, mock_packages
     of the original prefix, and leave the original spec marked installed.
     """
     # Get a build task. TODO: refactor this to avoid calling internal methods
-    const_arg = installer_args(["b"])
+    const_arg = installer_args(["pkg-b"], {})
     installer = create_installer(const_arg)
     installer._init_queue()
     task = installer._pop_task()
@@ -1343,7 +1342,7 @@ def remove(self, spec):
             self.called = True
 
     # Get a build task. TODO: refactor this to avoid calling internal methods
-    const_arg = installer_args(["b"])
+    const_arg = installer_args(["pkg-b"], {})
     installer = create_installer(const_arg)
     installer._init_queue()
     task = installer._pop_task()
@@ -1372,8 +1371,8 @@ def test_term_status_line():
     # accept that. `with log_output(buf)` doesn't really work because it trims output
     # and we actually want to test for escape sequences etc.
     x = inst.TermStatusLine(enabled=True)
-    x.add("a")
-    x.add("b")
+    x.add("pkg-a")
+    x.add("pkg-b")
     x.clear()
 
 
diff --git a/lib/spack/spack/test/mirror.py b/lib/spack/spack/test/mirror.py
index 450a5b282e..89bdf29436 100644
--- a/lib/spack/spack/test/mirror.py
+++ b/lib/spack/spack/test/mirror.py
@@ -289,8 +289,8 @@ def test_mirror_cache_symlinks(tmpdir):
 @pytest.mark.parametrize(
     "specs,expected_specs",
     [
-        (["a"], ["a@=1.0", "a@=2.0"]),
-        (["a", "brillig"], ["a@=1.0", "a@=2.0", "brillig@=1.0.0", "brillig@=2.0.0"]),
+        (["pkg-a"], ["pkg-a@=1.0", "pkg-a@=2.0"]),
+        (["pkg-a", "brillig"], ["pkg-a@=1.0", "pkg-a@=2.0", "brillig@=1.0.0", "brillig@=2.0.0"]),
     ],
 )
 def test_get_all_versions(specs, expected_specs):
diff --git a/lib/spack/spack/test/optional_deps.py b/lib/spack/spack/test/optional_deps.py
index e7a8676ab7..bf56c36991 100644
--- a/lib/spack/spack/test/optional_deps.py
+++ b/lib/spack/spack/test/optional_deps.py
@@ -13,28 +13,44 @@
         # Normalize simple conditionals
         ("optional-dep-test", {"optional-dep-test": None}),
         ("optional-dep-test~a", {"optional-dep-test~a": None}),
-        ("optional-dep-test+a", {"optional-dep-test+a": {"a": None}}),
-        ("optional-dep-test a=true", {"optional-dep-test a=true": {"a": None}}),
-        ("optional-dep-test a=true", {"optional-dep-test+a": {"a": None}}),
-        ("optional-dep-test@1.1", {"optional-dep-test@1.1": {"b": None}}),
-        ("optional-dep-test%intel", {"optional-dep-test%intel": {"c": None}}),
-        ("optional-dep-test%intel@64.1", {"optional-dep-test%intel@64.1": {"c": None, "d": None}}),
+        ("optional-dep-test+a", {"optional-dep-test+a": {"pkg-a": None}}),
+        ("optional-dep-test a=true", {"optional-dep-test a=true": {"pkg-a": None}}),
+        ("optional-dep-test a=true", {"optional-dep-test+a": {"pkg-a": None}}),
+        ("optional-dep-test@1.1", {"optional-dep-test@1.1": {"pkg-b": None}}),
+        ("optional-dep-test%intel", {"optional-dep-test%intel": {"pkg-c": None}}),
+        (
+            "optional-dep-test%intel@64.1",
+            {"optional-dep-test%intel@64.1": {"pkg-c": None, "pkg-d": None}},
+        ),
         (
             "optional-dep-test%intel@64.1.2",
-            {"optional-dep-test%intel@64.1.2": {"c": None, "d": None}},
+            {"optional-dep-test%intel@64.1.2": {"pkg-c": None, "pkg-d": None}},
         ),
-        ("optional-dep-test%clang@35", {"optional-dep-test%clang@35": {"e": None}}),
+        ("optional-dep-test%clang@35", {"optional-dep-test%clang@35": {"pkg-e": None}}),
         # Normalize multiple conditionals
-        ("optional-dep-test+a@1.1", {"optional-dep-test+a@1.1": {"a": None, "b": None}}),
-        ("optional-dep-test+a%intel", {"optional-dep-test+a%intel": {"a": None, "c": None}}),
-        ("optional-dep-test@1.1%intel", {"optional-dep-test@1.1%intel": {"b": None, "c": None}}),
+        ("optional-dep-test+a@1.1", {"optional-dep-test+a@1.1": {"pkg-a": None, "pkg-b": None}}),
+        (
+            "optional-dep-test+a%intel",
+            {"optional-dep-test+a%intel": {"pkg-a": None, "pkg-c": None}},
+        ),
+        (
+            "optional-dep-test@1.1%intel",
+            {"optional-dep-test@1.1%intel": {"pkg-b": None, "pkg-c": None}},
+        ),
         (
             "optional-dep-test@1.1%intel@64.1.2+a",
-            {"optional-dep-test@1.1%intel@64.1.2+a": {"a": None, "b": None, "c": None, "d": None}},
+            {
+                "optional-dep-test@1.1%intel@64.1.2+a": {
+                    "pkg-a": None,
+                    "pkg-b": None,
+                    "pkg-c": None,
+                    "pkg-d": None,
+                }
+            },
         ),
         (
             "optional-dep-test@1.1%clang@36.5+a",
-            {"optional-dep-test@1.1%clang@36.5+a": {"b": None, "a": None, "e": None}},
+            {"optional-dep-test@1.1%clang@36.5+a": {"pkg-b": None, "pkg-a": None, "pkg-e": None}},
         ),
         # Chained MPI
         (
@@ -44,7 +60,10 @@
         # Each of these dependencies comes from a conditional
         # dependency on another.  This requires iterating to evaluate
         # the whole chain.
-        ("optional-dep-test+f", {"optional-dep-test+f": {"f": None, "g": None, "mpi": None}}),
+        (
+            "optional-dep-test+f",
+            {"optional-dep-test+f": {"pkg-f": None, "pkg-g": None, "mpi": None}},
+        ),
     ]
 )
 def spec_and_expected(request):
@@ -63,12 +82,12 @@ def test_normalize(spec_and_expected, config, mock_packages):
 def test_default_variant(config, mock_packages):
     spec = Spec("optional-dep-test-3")
     spec.concretize()
-    assert "a" in spec
+    assert "pkg-a" in spec
 
     spec = Spec("optional-dep-test-3~var")
     spec.concretize()
-    assert "a" in spec
+    assert "pkg-a" in spec
 
     spec = Spec("optional-dep-test-3+var")
     spec.concretize()
-    assert "b" in spec
+    assert "pkg-b" in spec
diff --git a/lib/spack/spack/test/package_class.py b/lib/spack/spack/test/package_class.py
index 279693a529..05f7ca469b 100644
--- a/lib/spack/spack/test/package_class.py
+++ b/lib/spack/spack/test/package_class.py
@@ -21,6 +21,7 @@
 import spack.install_test
 import spack.package_base
 import spack.repo
+import spack.spec
 from spack.build_systems.generic import Package
 from spack.installer import InstallError
 
@@ -141,19 +142,19 @@ def setup_install_test(source_paths, test_root):
     "spec,sources,extras,expect",
     [
         (
-            "a",
+            "pkg-a",
             ["example/a.c"],  # Source(s)
             ["example/a.c"],  # Extra test source
             ["example/a.c"],
         ),  # Test install dir source(s)
         (
-            "b",
+            "pkg-b",
             ["test/b.cpp", "test/b.hpp", "example/b.txt"],  # Source(s)
             ["test"],  # Extra test source
             ["test/b.cpp", "test/b.hpp"],
         ),  # Test install dir source
         (
-            "c",
+            "pkg-c",
             ["examples/a.py", "examples/b.py", "examples/c.py", "tests/d.py"],
             ["examples/b.py", "tests"],
             ["examples/b.py", "tests/d.py"],
@@ -201,7 +202,7 @@ def test_cache_extra_sources(install_mockery, spec, sources, extras, expect):
 
 
 def test_cache_extra_sources_fails(install_mockery):
-    s = spack.spec.Spec("a").concretized()
+    s = spack.spec.Spec("pkg-a").concretized()
     s.package.spec.concretize()
 
     with pytest.raises(InstallError) as exc_info:
@@ -225,7 +226,7 @@ class URLsPackage(spack.package.Package):
         url = "https://www.example.com/url-package-1.0.tgz"
         urls = ["https://www.example.com/archive"]
 
-    s = spack.spec.Spec("a")
+    s = spack.spec.Spec("pkg-a")
     with pytest.raises(ValueError, match="defines both"):
         URLsPackage(s)
 
@@ -235,7 +236,7 @@ class LicensedPackage(spack.package.Package):
         extendees = None  # currently a required attribute for is_extension()
         license_files = None
 
-    s = spack.spec.Spec("a")
+    s = spack.spec.Spec("pkg-a")
     pkg = LicensedPackage(s)
     assert pkg.global_license_file is None
 
@@ -248,21 +249,21 @@ class BaseTestPackage(Package):
 
 
 def test_package_version_fails():
-    s = spack.spec.Spec("a")
+    s = spack.spec.Spec("pkg-a")
     pkg = BaseTestPackage(s)
     with pytest.raises(ValueError, match="does not have a concrete version"):
         pkg.version()
 
 
 def test_package_tester_fails():
-    s = spack.spec.Spec("a")
+    s = spack.spec.Spec("pkg-a")
     pkg = BaseTestPackage(s)
     with pytest.raises(ValueError, match="without concrete version"):
         pkg.tester()
 
 
 def test_package_fetcher_fails():
-    s = spack.spec.Spec("a")
+    s = spack.spec.Spec("pkg-a")
     pkg = BaseTestPackage(s)
     with pytest.raises(ValueError, match="without concrete version"):
         pkg.fetcher
@@ -280,7 +281,7 @@ def compilers(compiler, arch_spec):
 
     monkeypatch.setattr(spack.compilers, "compilers_for_spec", compilers)
 
-    s = spack.spec.Spec("a")
+    s = spack.spec.Spec("pkg-a")
     pkg = BaseTestPackage(s)
     pkg.test_requires_compiler = True
     pkg.do_test()
diff --git a/lib/spack/spack/test/packaging.py b/lib/spack/spack/test/packaging.py
index bd49cf94ae..54e53ffe74 100644
--- a/lib/spack/spack/test/packaging.py
+++ b/lib/spack/spack/test/packaging.py
@@ -517,7 +517,7 @@ def test_manual_download(
     def _instr(pkg):
         return f"Download instructions for {pkg.spec.name}"
 
-    spec = default_mock_concretization("a")
+    spec = default_mock_concretization("pkg-a")
     spec.package.manual_download = manual
     if instr:
         monkeypatch.setattr(spack.package_base.PackageBase, "download_instr", _instr)
@@ -543,7 +543,7 @@ def test_fetch_without_code_is_noop(
     default_mock_concretization, install_mockery, fetching_not_allowed
 ):
     """do_fetch for packages without code should be a no-op"""
-    pkg = default_mock_concretization("a").package
+    pkg = default_mock_concretization("pkg-a").package
     pkg.has_code = False
     pkg.do_fetch()
 
@@ -552,7 +552,7 @@ def test_fetch_external_package_is_noop(
     default_mock_concretization, install_mockery, fetching_not_allowed
 ):
     """do_fetch for packages without code should be a no-op"""
-    spec = default_mock_concretization("a")
+    spec = default_mock_concretization("pkg-a")
     spec.external_path = "/some/where"
     assert spec.external
     spec.package.do_fetch()
diff --git a/lib/spack/spack/test/repo.py b/lib/spack/spack/test/repo.py
index eb6b123916..89a394cd67 100644
--- a/lib/spack/spack/test/repo.py
+++ b/lib/spack/spack/test/repo.py
@@ -9,6 +9,8 @@
 import spack.package_base
 import spack.paths
 import spack.repo
+import spack.spec
+import spack.util.file_cache
 
 
 @pytest.fixture(params=["packages", "", "foo"])
@@ -30,25 +32,25 @@ def extra_repo(tmpdir_factory, request):
 
 
 def test_repo_getpkg(mutable_mock_repo):
-    mutable_mock_repo.get_pkg_class("a")
-    mutable_mock_repo.get_pkg_class("builtin.mock.a")
+    mutable_mock_repo.get_pkg_class("pkg-a")
+    mutable_mock_repo.get_pkg_class("builtin.mock.pkg-a")
 
 
 def test_repo_multi_getpkg(mutable_mock_repo, extra_repo):
     mutable_mock_repo.put_first(extra_repo[0])
-    mutable_mock_repo.get_pkg_class("a")
-    mutable_mock_repo.get_pkg_class("builtin.mock.a")
+    mutable_mock_repo.get_pkg_class("pkg-a")
+    mutable_mock_repo.get_pkg_class("builtin.mock.pkg-a")
 
 
 def test_repo_multi_getpkgclass(mutable_mock_repo, extra_repo):
     mutable_mock_repo.put_first(extra_repo[0])
-    mutable_mock_repo.get_pkg_class("a")
-    mutable_mock_repo.get_pkg_class("builtin.mock.a")
+    mutable_mock_repo.get_pkg_class("pkg-a")
+    mutable_mock_repo.get_pkg_class("builtin.mock.pkg-a")
 
 
 def test_repo_pkg_with_unknown_namespace(mutable_mock_repo):
     with pytest.raises(spack.repo.UnknownNamespaceError):
-        mutable_mock_repo.get_pkg_class("unknown.a")
+        mutable_mock_repo.get_pkg_class("unknown.pkg-a")
 
 
 def test_repo_unknown_pkg(mutable_mock_repo):
@@ -142,14 +144,14 @@ def test_get_all_mock_packages(mock_packages):
 
 def test_repo_path_handles_package_removal(tmpdir, mock_packages):
     builder = spack.repo.MockRepositoryBuilder(tmpdir, namespace="removal")
-    builder.add_package("c")
+    builder.add_package("pkg-c")
     with spack.repo.use_repositories(builder.root, override=False) as repos:
-        r = repos.repo_for_pkg("c")
+        r = repos.repo_for_pkg("pkg-c")
         assert r.namespace == "removal"
 
-    builder.remove("c")
+    builder.remove("pkg-c")
     with spack.repo.use_repositories(builder.root, override=False) as repos:
-        r = repos.repo_for_pkg("c")
+        r = repos.repo_for_pkg("pkg-c")
         assert r.namespace == "builtin.mock"
 
 
diff --git a/lib/spack/spack/test/spec_dag.py b/lib/spack/spack/test/spec_dag.py
index 3a9c0350ae..f1b16b80a7 100644
--- a/lib/spack/spack/test/spec_dag.py
+++ b/lib/spack/spack/test/spec_dag.py
@@ -138,19 +138,19 @@ def test_specify_preinstalled_dep(tmpdir, monkeypatch):
     transitive dependency that is only supplied by the preinstalled package.
     """
     builder = spack.repo.MockRepositoryBuilder(tmpdir)
-    builder.add_package("c")
-    builder.add_package("b", dependencies=[("c", None, None)])
-    builder.add_package("a", dependencies=[("b", None, None)])
+    builder.add_package("pkg-c")
+    builder.add_package("pkg-b", dependencies=[("pkg-c", None, None)])
+    builder.add_package("pkg-a", dependencies=[("pkg-b", None, None)])
 
     with spack.repo.use_repositories(builder.root):
-        b_spec = Spec("b").concretized()
-        monkeypatch.setattr(Spec, "installed", property(lambda x: x.name != "a"))
+        b_spec = Spec("pkg-b").concretized()
+        monkeypatch.setattr(Spec, "installed", property(lambda x: x.name != "pkg-a"))
 
-        a_spec = Spec("a")
+        a_spec = Spec("pkg-a")
         a_spec._add_dependency(b_spec, depflag=dt.BUILD | dt.LINK, virtuals=())
         a_spec.concretize()
 
-        assert set(x.name for x in a_spec.traverse()) == set(["a", "b", "c"])
+        assert {x.name for x in a_spec.traverse()} == {"pkg-a", "pkg-b", "pkg-c"}
 
 
 @pytest.mark.usefixtures("config")
@@ -982,15 +982,15 @@ def test_synthetic_construction_of_split_dependencies_from_same_package(mock_pac
     # Construct in a synthetic way (i.e. without using the solver)
     # the following spec:
     #
-    #          b
+    #        pkg-b
     #  build /   \ link,run
-    #    c@2.0   c@1.0
+    #  pkg-c@2.0   pkg-c@1.0
     #
     # To demonstrate that a spec can now hold two direct
     # dependencies from the same package
-    root = Spec("b").concretized()
-    link_run_spec = Spec("c@=1.0").concretized()
-    build_spec = Spec("c@=2.0").concretized()
+    root = Spec("pkg-b").concretized()
+    link_run_spec = Spec("pkg-c@=1.0").concretized()
+    build_spec = Spec("pkg-c@=2.0").concretized()
 
     root.add_dependency_edge(link_run_spec, depflag=dt.LINK, virtuals=())
     root.add_dependency_edge(link_run_spec, depflag=dt.RUN, virtuals=())
@@ -998,10 +998,10 @@ def test_synthetic_construction_of_split_dependencies_from_same_package(mock_pac
 
     # Check dependencies from the perspective of root
     assert len(root.dependencies()) == 2
-    assert all(x.name == "c" for x in root.dependencies())
+    assert all(x.name == "pkg-c" for x in root.dependencies())
 
-    assert "@2.0" in root.dependencies(name="c", deptype=dt.BUILD)[0]
-    assert "@1.0" in root.dependencies(name="c", deptype=dt.LINK | dt.RUN)[0]
+    assert "@2.0" in root.dependencies(name="pkg-c", deptype=dt.BUILD)[0]
+    assert "@1.0" in root.dependencies(name="pkg-c", deptype=dt.LINK | dt.RUN)[0]
 
     # Check parent from the perspective of the dependencies
     assert len(build_spec.dependents()) == 1
@@ -1013,30 +1013,30 @@ def test_synthetic_construction_of_split_dependencies_from_same_package(mock_pac
 def test_synthetic_construction_bootstrapping(mock_packages, config):
     # Construct the following spec:
     #
-    #  b@2.0
+    #  pkg-b@2.0
     #    | build
-    #  b@1.0
+    #  pkg-b@1.0
     #
-    root = Spec("b@=2.0").concretized()
-    bootstrap = Spec("b@=1.0").concretized()
+    root = Spec("pkg-b@=2.0").concretized()
+    bootstrap = Spec("pkg-b@=1.0").concretized()
 
     root.add_dependency_edge(bootstrap, depflag=dt.BUILD, virtuals=())
 
     assert len(root.dependencies()) == 1
-    assert root.dependencies()[0].name == "b"
-    assert root.name == "b"
+    assert root.dependencies()[0].name == "pkg-b"
+    assert root.name == "pkg-b"
 
 
 def test_addition_of_different_deptypes_in_multiple_calls(mock_packages, config):
     # Construct the following spec:
     #
-    #  b@2.0
+    #  pkg-b@2.0
     #    | build,link,run
-    #  b@1.0
+    #  pkg-b@1.0
     #
     # with three calls and check we always have a single edge
-    root = Spec("b@=2.0").concretized()
-    bootstrap = Spec("b@=1.0").concretized()
+    root = Spec("pkg-b@=2.0").concretized()
+    bootstrap = Spec("pkg-b@=1.0").concretized()
 
     for current_depflag in (dt.BUILD, dt.LINK, dt.RUN):
         root.add_dependency_edge(bootstrap, depflag=current_depflag, virtuals=())
@@ -1063,9 +1063,9 @@ def test_addition_of_different_deptypes_in_multiple_calls(mock_packages, config)
 def test_adding_same_deptype_with_the_same_name_raises(
     mock_packages, config, c1_depflag, c2_depflag
 ):
-    p = Spec("b@=2.0").concretized()
-    c1 = Spec("b@=1.0").concretized()
-    c2 = Spec("b@=2.0").concretized()
+    p = Spec("pkg-b@=2.0").concretized()
+    c1 = Spec("pkg-b@=1.0").concretized()
+    c2 = Spec("pkg-b@=2.0").concretized()
 
     p.add_dependency_edge(c1, depflag=c1_depflag, virtuals=())
     with pytest.raises(spack.error.SpackError):
diff --git a/lib/spack/spack/test/spec_semantics.py b/lib/spack/spack/test/spec_semantics.py
index e0481c5967..d8029d313c 100644
--- a/lib/spack/spack/test/spec_semantics.py
+++ b/lib/spack/spack/test/spec_semantics.py
@@ -373,7 +373,7 @@ def test_satisfies_single_valued_variant(self):
         https://github.com/spack/spack/pull/2386#issuecomment-282147639
         is handled correctly.
         """
-        a = Spec("a foobar=bar")
+        a = Spec("pkg-a foobar=bar")
         a.concretize()
 
         assert a.satisfies("foobar=bar")
@@ -390,21 +390,21 @@ def test_satisfies_single_valued_variant(self):
         assert "foo=bar" in a
 
         # Check that conditional dependencies are treated correctly
-        assert "^b" in a
+        assert "^pkg-b" in a
 
     def test_unsatisfied_single_valued_variant(self):
-        a = Spec("a foobar=baz")
+        a = Spec("pkg-a foobar=baz")
         a.concretize()
-        assert "^b" not in a
+        assert "^pkg-b" not in a
 
         mv = Spec("multivalue-variant")
         mv.concretize()
-        assert "a@1.0" not in mv
+        assert "pkg-a@1.0" not in mv
 
     def test_indirect_unsatisfied_single_valued_variant(self):
         spec = Spec("singlevalue-variant-dependent")
         spec.concretize()
-        assert "a@1.0" not in spec
+        assert "pkg-a@1.0" not in spec
 
     def test_unsatisfiable_multi_value_variant(self, default_mock_concretization):
         # Semantics for a multi-valued variant is different
@@ -982,8 +982,8 @@ def test_splice_swap_names_mismatch_virtuals(self, default_mock_concretization,
             spec.splice(dep, transitive)
 
     def test_spec_override(self):
-        init_spec = Spec("a foo=baz foobar=baz cflags=-O3 cxxflags=-O1")
-        change_spec = Spec("a foo=fee cflags=-O2")
+        init_spec = Spec("pkg-a foo=baz foobar=baz cflags=-O3 cxxflags=-O1")
+        change_spec = Spec("pkg-a foo=fee cflags=-O2")
         new_spec = Spec.override(init_spec, change_spec)
         new_spec.concretize()
         assert "foo=fee" in new_spec
@@ -1253,15 +1253,15 @@ def test_spec_installed(default_mock_concretization, database):
     spec = Spec("not-a-real-package")
     assert not spec.installed
 
-    # 'a' is not in the mock DB and is not installed
-    spec = default_mock_concretization("a")
+    # pkg-a is not in the mock DB and is not installed
+    spec = default_mock_concretization("pkg-a")
     assert not spec.installed
 
 
 @pytest.mark.regression("30678")
 def test_call_dag_hash_on_old_dag_hash_spec(mock_packages, default_mock_concretization):
     # create a concrete spec
-    a = default_mock_concretization("a")
+    a = default_mock_concretization("pkg-a")
     dag_hashes = {spec.name: spec.dag_hash() for spec in a.traverse()}
 
     # make it look like an old DAG hash spec with no package hash on the spec.
@@ -1309,8 +1309,8 @@ def test_unsupported_compiler():
 
 
 def test_package_hash_affects_dunder_and_dag_hash(mock_packages, default_mock_concretization):
-    a1 = default_mock_concretization("a")
-    a2 = default_mock_concretization("a")
+    a1 = default_mock_concretization("pkg-a")
+    a2 = default_mock_concretization("pkg-a")
 
     assert hash(a1) == hash(a2)
     assert a1.dag_hash() == a2.dag_hash()
@@ -1334,8 +1334,8 @@ def test_intersects_and_satisfies_on_concretized_spec(default_mock_concretizatio
     """Test that a spec obtained by concretizing an abstract spec, satisfies the abstract spec
     but not vice-versa.
     """
-    a1 = default_mock_concretization("a@1.0")
-    a2 = Spec("a@1.0")
+    a1 = default_mock_concretization("pkg-a@1.0")
+    a2 = Spec("pkg-a@1.0")
 
     assert a1.intersects(a2)
     assert a2.intersects(a1)
@@ -1461,17 +1461,17 @@ def test_constrain(factory, lhs_str, rhs_str, result, constrained_str):
 
 
 def test_abstract_hash_intersects_and_satisfies(default_mock_concretization):
-    concrete: Spec = default_mock_concretization("a")
+    concrete: Spec = default_mock_concretization("pkg-a")
     hash = concrete.dag_hash()
     hash_5 = hash[:5]
     hash_6 = hash[:6]
     # abstract hash that doesn't have a common prefix with the others.
     hash_other = f"{'a' if hash_5[0] == 'b' else 'b'}{hash_5[1:]}"
 
-    abstract_5 = Spec(f"a/{hash_5}")
-    abstract_6 = Spec(f"a/{hash_6}")
-    abstract_none = Spec(f"a/{hash_other}")
-    abstract = Spec("a")
+    abstract_5 = Spec(f"pkg-a/{hash_5}")
+    abstract_6 = Spec(f"pkg-a/{hash_6}")
+    abstract_none = Spec(f"pkg-a/{hash_other}")
+    abstract = Spec("pkg-a")
 
     def assert_subset(a: Spec, b: Spec):
         assert a.intersects(b) and b.intersects(a) and a.satisfies(b) and not b.satisfies(a)
@@ -1508,6 +1508,6 @@ def test_edge_equality_does_not_depend_on_virtual_order():
 
 
 def test_old_format_strings_trigger_error(default_mock_concretization):
-    s = Spec("a").concretized()
+    s = Spec("pkg-a").concretized()
     with pytest.raises(SpecFormatStringError):
         s.format("${PACKAGE}-${VERSION}-${HASH}")
diff --git a/lib/spack/spack/test/spec_syntax.py b/lib/spack/spack/test/spec_syntax.py
index 3cbb59e69f..c1116fd916 100644
--- a/lib/spack/spack/test/spec_syntax.py
+++ b/lib/spack/spack/test/spec_syntax.py
@@ -699,7 +699,7 @@ def test_spec_by_hash_tokens(text, tokens):
 @pytest.mark.db
 def test_spec_by_hash(database, monkeypatch, config):
     mpileaks = database.query_one("mpileaks ^zmpi")
-    b = spack.spec.Spec("b").concretized()
+    b = spack.spec.Spec("pkg-b").concretized()
     monkeypatch.setattr(spack.binary_distribution, "update_cache_and_get_specs", lambda: [b])
 
     hash_str = f"/{mpileaks.dag_hash()}"
@@ -796,7 +796,7 @@ def test_ambiguous_hash(mutable_database, default_mock_concretization, config):
     In the past this ambiguity error would happen during parse time."""
 
     # This is a very sketchy as manually setting hashes easily breaks invariants
-    x1 = default_mock_concretization("a")
+    x1 = spack.spec.Spec("pkg-a").concretized()
     x2 = x1.copy()
     x1._hash = "xyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy"
     x1._process_hash = "xyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy"
@@ -814,7 +814,7 @@ def test_ambiguous_hash(mutable_database, default_mock_concretization, config):
         s1.lookup_hash()
 
     # ambiguity in first hash character AND spec name
-    s2 = SpecParser("a/x").next_spec()
+    s2 = SpecParser("pkg-a/x").next_spec()
     with pytest.raises(spack.spec.AmbiguousHashError):
         s2.lookup_hash()
 
diff --git a/lib/spack/spack/test/spec_yaml.py b/lib/spack/spack/test/spec_yaml.py
index b19bb4308f..7da8fad623 100644
--- a/lib/spack/spack/test/spec_yaml.py
+++ b/lib/spack/spack/test/spec_yaml.py
@@ -314,23 +314,23 @@ def test_save_dependency_spec_jsons_subset(tmpdir, config):
     output_path = str(tmpdir.mkdir("spec_jsons"))
 
     builder = spack.repo.MockRepositoryBuilder(tmpdir.mkdir("mock-repo"))
-    builder.add_package("g")
-    builder.add_package("f")
-    builder.add_package("e")
-    builder.add_package("d", dependencies=[("f", None, None), ("g", None, None)])
-    builder.add_package("c")
-    builder.add_package("b", dependencies=[("d", None, None), ("e", None, None)])
-    builder.add_package("a", dependencies=[("b", None, None), ("c", None, None)])
+    builder.add_package("pkg-g")
+    builder.add_package("pkg-f")
+    builder.add_package("pkg-e")
+    builder.add_package("pkg-d", dependencies=[("pkg-f", None, None), ("pkg-g", None, None)])
+    builder.add_package("pkg-c")
+    builder.add_package("pkg-b", dependencies=[("pkg-d", None, None), ("pkg-e", None, None)])
+    builder.add_package("pkg-a", dependencies=[("pkg-b", None, None), ("pkg-c", None, None)])
 
     with spack.repo.use_repositories(builder.root):
-        spec_a = Spec("a").concretized()
-        b_spec = spec_a["b"]
-        c_spec = spec_a["c"]
+        spec_a = Spec("pkg-a").concretized()
+        b_spec = spec_a["pkg-b"]
+        c_spec = spec_a["pkg-c"]
 
-        save_dependency_specfiles(spec_a, output_path, [Spec("b"), Spec("c")])
+        save_dependency_specfiles(spec_a, output_path, [Spec("pkg-b"), Spec("pkg-c")])
 
-        assert check_specs_equal(b_spec, os.path.join(output_path, "b.json"))
-        assert check_specs_equal(c_spec, os.path.join(output_path, "c.json"))
+        assert check_specs_equal(b_spec, os.path.join(output_path, "pkg-b.json"))
+        assert check_specs_equal(c_spec, os.path.join(output_path, "pkg-c.json"))
 
 
 def test_legacy_yaml(tmpdir, install_mockery, mock_packages):
diff --git a/lib/spack/spack/test/test_suite.py b/lib/spack/spack/test/test_suite.py
index cf7d32322e..4b9e83b8a4 100644
--- a/lib/spack/spack/test/test_suite.py
+++ b/lib/spack/spack/test/test_suite.py
@@ -519,7 +519,7 @@ def test_find_required_file(tmpdir):
 def test_packagetest_fails(mock_packages):
     MyPackage = collections.namedtuple("MyPackage", ["spec"])
 
-    s = spack.spec.Spec("a")
+    s = spack.spec.Spec("pkg-a")
     pkg = MyPackage(s)
     with pytest.raises(ValueError, match="require a concrete package"):
         spack.install_test.PackageTest(pkg)
diff --git a/lib/spack/spack/test/views.py b/lib/spack/spack/test/views.py
index 4df1da7e40..c5f27d6c64 100644
--- a/lib/spack/spack/test/views.py
+++ b/lib/spack/spack/test/views.py
@@ -33,8 +33,8 @@ def test_view_with_spec_not_contributing_files(mock_packages, tmpdir):
     layout = DirectoryLayout(view_dir)
     view = SimpleFilesystemView(view_dir, layout)
 
-    a = Spec("a")
-    b = Spec("b")
+    a = Spec("pkg-a")
+    b = Spec("pkg-b")
     a.prefix = os.path.join(tmpdir, "a")
     b.prefix = os.path.join(tmpdir, "b")
     a._mark_concrete()
diff --git a/var/spack/repos/builtin.mock/packages/depb/package.py b/var/spack/repos/builtin.mock/packages/depb/package.py
index 1d9a12ad83..5104d7e428 100644
--- a/var/spack/repos/builtin.mock/packages/depb/package.py
+++ b/var/spack/repos/builtin.mock/packages/depb/package.py
@@ -14,7 +14,7 @@ class Depb(AutotoolsPackage):
 
     version("1.0", md5="0123456789abcdef0123456789abcdef")
 
-    depends_on("b")
+    depends_on("pkg-b")
 
     def install(self, spec, prefix):
         # sanity_check_prefix requires something in the install directory
diff --git a/var/spack/repos/builtin.mock/packages/external-buildable-with-variant/package.py b/var/spack/repos/builtin.mock/packages/external-buildable-with-variant/package.py
index afedaadba3..f9075bbd3d 100644
--- a/var/spack/repos/builtin.mock/packages/external-buildable-with-variant/package.py
+++ b/var/spack/repos/builtin.mock/packages/external-buildable-with-variant/package.py
@@ -15,4 +15,4 @@ class ExternalBuildableWithVariant(Package):
 
     variant("baz", default=False, description="nope")
 
-    depends_on("c@1.0", when="@0.9")
+    depends_on("pkg-c@1.0", when="@0.9")
diff --git a/var/spack/repos/builtin.mock/packages/missing-dependency/package.py b/var/spack/repos/builtin.mock/packages/missing-dependency/package.py
index 668df13978..41ad296d3d 100644
--- a/var/spack/repos/builtin.mock/packages/missing-dependency/package.py
+++ b/var/spack/repos/builtin.mock/packages/missing-dependency/package.py
@@ -18,4 +18,4 @@ class MissingDependency(Package):
     depends_on("this-is-a-missing-dependency")
 
     # this one is a "real" mock dependency
-    depends_on("a")
+    depends_on("pkg-a")
diff --git a/var/spack/repos/builtin.mock/packages/multivalue-variant/package.py b/var/spack/repos/builtin.mock/packages/multivalue-variant/package.py
index b0f7ac9501..17a68659cc 100644
--- a/var/spack/repos/builtin.mock/packages/multivalue-variant/package.py
+++ b/var/spack/repos/builtin.mock/packages/multivalue-variant/package.py
@@ -40,5 +40,5 @@ class MultivalueVariant(Package):
 
     depends_on("mpi")
     depends_on("callpath")
-    depends_on("a")
-    depends_on("a@1.0", when="fee=barbaz")
+    depends_on("pkg-a")
+    depends_on("pkg-a@1.0", when="fee=barbaz")
diff --git a/var/spack/repos/builtin.mock/packages/optional-dep-test-3/package.py b/var/spack/repos/builtin.mock/packages/optional-dep-test-3/package.py
index 4b89ef6750..05c2d36833 100644
--- a/var/spack/repos/builtin.mock/packages/optional-dep-test-3/package.py
+++ b/var/spack/repos/builtin.mock/packages/optional-dep-test-3/package.py
@@ -16,5 +16,5 @@ class OptionalDepTest3(Package):
 
     variant("var", default=False)
 
-    depends_on("a", when="~var")
-    depends_on("b", when="+var")
+    depends_on("pkg-a", when="~var")
+    depends_on("pkg-b", when="+var")
diff --git a/var/spack/repos/builtin.mock/packages/optional-dep-test/package.py b/var/spack/repos/builtin.mock/packages/optional-dep-test/package.py
index 4037623cdd..6b34e05246 100644
--- a/var/spack/repos/builtin.mock/packages/optional-dep-test/package.py
+++ b/var/spack/repos/builtin.mock/packages/optional-dep-test/package.py
@@ -19,14 +19,14 @@ class OptionalDepTest(Package):
     variant("f", default=False)
     variant("mpi", default=False)
 
-    depends_on("a", when="+a")
-    depends_on("b", when="@1.1")
-    depends_on("c", when="%intel")
-    depends_on("d", when="%intel@64.1")
-    depends_on("e", when="%clang@34:40")
+    depends_on("pkg-a", when="+a")
+    depends_on("pkg-b", when="@1.1")
+    depends_on("pkg-c", when="%intel")
+    depends_on("pkg-d", when="%intel@64.1")
+    depends_on("pkg-e", when="%clang@34:40")
 
-    depends_on("f", when="+f")
-    depends_on("g", when="^f")
-    depends_on("mpi", when="^g")
+    depends_on("pkg-f", when="+f")
+    depends_on("pkg-g", when="^pkg-f")
+    depends_on("mpi", when="^pkg-g")
 
     depends_on("mpi", when="+mpi")
diff --git a/var/spack/repos/builtin.mock/packages/a/package.py b/var/spack/repos/builtin.mock/packages/pkg-a/package.py
similarity index 95%
rename from var/spack/repos/builtin.mock/packages/a/package.py
rename to var/spack/repos/builtin.mock/packages/pkg-a/package.py
index ba6064bd59..207aabe087 100644
--- a/var/spack/repos/builtin.mock/packages/a/package.py
+++ b/var/spack/repos/builtin.mock/packages/pkg-a/package.py
@@ -6,7 +6,7 @@
 from spack.package import *
 
 
-class A(AutotoolsPackage):
+class PkgA(AutotoolsPackage):
     """Simple package with one optional dependency"""
 
     homepage = "http://www.example.com"
@@ -25,7 +25,7 @@ class A(AutotoolsPackage):
 
     variant("bvv", default=True, description="The good old BV variant")
 
-    depends_on("b", when="foobar=bar")
+    depends_on("pkg-b", when="foobar=bar")
     depends_on("test-dependency", type="test")
 
     parallel = False
diff --git a/var/spack/repos/builtin.mock/packages/b/package.py b/var/spack/repos/builtin.mock/packages/pkg-b/package.py
similarity index 96%
rename from var/spack/repos/builtin.mock/packages/b/package.py
rename to var/spack/repos/builtin.mock/packages/pkg-b/package.py
index 1685711825..210ef16ab9 100644
--- a/var/spack/repos/builtin.mock/packages/b/package.py
+++ b/var/spack/repos/builtin.mock/packages/pkg-b/package.py
@@ -6,7 +6,7 @@
 from spack.package import *
 
 
-class B(Package):
+class PkgB(Package):
     """Simple package with no dependencies"""
 
     homepage = "http://www.example.com"
diff --git a/var/spack/repos/builtin.mock/packages/c/package.py b/var/spack/repos/builtin.mock/packages/pkg-c/package.py
similarity index 95%
rename from var/spack/repos/builtin.mock/packages/c/package.py
rename to var/spack/repos/builtin.mock/packages/pkg-c/package.py
index 0ef4e2f80a..69adf063a7 100644
--- a/var/spack/repos/builtin.mock/packages/c/package.py
+++ b/var/spack/repos/builtin.mock/packages/pkg-c/package.py
@@ -6,7 +6,7 @@
 from spack.package import *
 
 
-class C(Package):
+class PkgC(Package):
     """Simple package with no dependencies"""
 
     homepage = "http://www.example.com"
diff --git a/var/spack/repos/builtin.mock/packages/e/package.py b/var/spack/repos/builtin.mock/packages/pkg-e/package.py
similarity index 95%
rename from var/spack/repos/builtin.mock/packages/e/package.py
rename to var/spack/repos/builtin.mock/packages/pkg-e/package.py
index a1ed6834bd..c4ecbbdca3 100644
--- a/var/spack/repos/builtin.mock/packages/e/package.py
+++ b/var/spack/repos/builtin.mock/packages/pkg-e/package.py
@@ -6,7 +6,7 @@
 from spack.package import *
 
 
-class E(Package):
+class PkgE(Package):
     """Simple package with no dependencies"""
 
     homepage = "http://www.example.com"
diff --git a/var/spack/repos/builtin.mock/packages/test-dep-with-imposed-conditions/package.py b/var/spack/repos/builtin.mock/packages/test-dep-with-imposed-conditions/package.py
index aadd47e335..93a01bd5dc 100644
--- a/var/spack/repos/builtin.mock/packages/test-dep-with-imposed-conditions/package.py
+++ b/var/spack/repos/builtin.mock/packages/test-dep-with-imposed-conditions/package.py
@@ -14,4 +14,4 @@ class TestDepWithImposedConditions(Package):
 
     version("1.0", md5="0123456789abcdef0123456789abcdef")
 
-    depends_on("c@1.0", type="test")
+    depends_on("pkg-c@1.0", type="test")
diff --git a/var/spack/repos/builtin.mock/packages/vendorsb/package.py b/var/spack/repos/builtin.mock/packages/vendorsb/package.py
index fbf14236a1..21eed17061 100644
--- a/var/spack/repos/builtin.mock/packages/vendorsb/package.py
+++ b/var/spack/repos/builtin.mock/packages/vendorsb/package.py
@@ -15,5 +15,5 @@ class Vendorsb(Package):
     version("1.1", md5="0123456789abcdef0123456789abcdef")
     version("1.0", md5="0123456789abcdef0123456789abcdef")
 
-    # b is not a dependency
-    conflicts("b", when="@=1.1")
+    # pkg-b is not a dependency
+    conflicts("pkg-b", when="@=1.1")
diff --git a/var/spack/repos/builtin.mock/packages/when-directives-false/package.py b/var/spack/repos/builtin.mock/packages/when-directives-false/package.py
index 94ec3f7e30..27952d4c28 100644
--- a/var/spack/repos/builtin.mock/packages/when-directives-false/package.py
+++ b/var/spack/repos/builtin.mock/packages/when-directives-false/package.py
@@ -20,7 +20,7 @@ class WhenDirectivesFalse(Package):
         when=False,
     )
     extends("extendee", when=False)
-    depends_on("b", when=False)
+    depends_on("pkg-b", when=False)
     conflicts("@1.0", when=False)
     resource(
         url="http://www.example.com/example-1.0-resource.tar.gz",
diff --git a/var/spack/repos/builtin.mock/packages/when-directives-true/package.py b/var/spack/repos/builtin.mock/packages/when-directives-true/package.py
index 7aa0047e2c..42ac7caa90 100644
--- a/var/spack/repos/builtin.mock/packages/when-directives-true/package.py
+++ b/var/spack/repos/builtin.mock/packages/when-directives-true/package.py
@@ -20,7 +20,7 @@ class WhenDirectivesTrue(Package):
         when=True,
     )
     extends("extendee", when=True)
-    depends_on("b", when=True)
+    depends_on("pkg-b", when=True)
     conflicts("@1.0", when=True)
     resource(
         url="http://www.example.com/example-1.0-resource.tar.gz",
diff --git a/var/spack/repos/builtin.mock/packages/with-constraint-met/package.py b/var/spack/repos/builtin.mock/packages/with-constraint-met/package.py
index cf431ae5ec..306df2c42d 100644
--- a/var/spack/repos/builtin.mock/packages/with-constraint-met/package.py
+++ b/var/spack/repos/builtin.mock/packages/with-constraint-met/package.py
@@ -16,8 +16,8 @@ class WithConstraintMet(Package):
     version("1.0", md5="0123456789abcdef0123456789abcdef")
 
     with when("@1.0"):
-        depends_on("b")
+        depends_on("pkg-b")
         conflicts("%gcc", when="+foo")
 
-    with when("@0.14: ^b@:4.0"):
-        depends_on("c", when="@:15 ^b@3.8:")
+    with when("@0.14: ^pkg-b@:4.0"):
+        depends_on("pkg-c", when="@:15 ^pkg-b@3.8:")
diff --git a/var/spack/repos/builtin.mock/packages/wrong-variant-in-depends-on/package.py b/var/spack/repos/builtin.mock/packages/wrong-variant-in-depends-on/package.py
index 8cb8b61508..92727fced0 100644
--- a/var/spack/repos/builtin.mock/packages/wrong-variant-in-depends-on/package.py
+++ b/var/spack/repos/builtin.mock/packages/wrong-variant-in-depends-on/package.py
@@ -13,4 +13,4 @@ class WrongVariantInDependsOn(Package):
 
     version("1.0", md5="0123456789abcdef0123456789abcdef")
 
-    depends_on("b+doesnotexist")
+    depends_on("pkg-b+doesnotexist")