Pipelines: Compare target family instead of architecture (#19884)

In compiler bootstrapping pipelines, we add an artificial dependency
between jobs for packages to be built with a bootstrapped compiler
and the job building the compiler.  To find the right bootstrapped
compiler for each spec, we compared not only the compiler spec to
that required by the package spec, but also the architectures of
the compiler and package spec.

But this prevented us from finding the bootstrapped compiler for a
spec in cases where the architecture of the compiler wasn't exactly
the same as the spec.  For example, a gcc@4.8.5 might have 
bootstrapped a compiler with haswell as the architecture, while the 
spec had broadwell.  By comparing the families instead of the architecture
 itself, we know that we can build the zlib for broadwell with the gcc for 
haswell.

lib/spack/spack/ci.py

@@ -691,12 +691,19 @@ def generate_gitlab_ci_yaml(env, print_summary, output_file,
                 # bootstrap spec lists, then we will add more dependencies to
                 # the job (that compiler and maybe it's dependencies as well).
                 if is_main_phase(phase_name):
+                    spec_arch_family = (release_spec.architecture
+                                                    .target
+                                                    .microarchitecture
+                                                    .family)
                     compiler_pkg_spec = compilers.pkg_spec_for_compiler(
                         release_spec.compiler)
                     for bs in bootstrap_specs:
                         bs_arch = bs['spec'].architecture
+                        bs_arch_family = (bs_arch.target
+                                                 .microarchitecture
+                                                 .family)
                         if (bs['spec'].satisfies(compiler_pkg_spec) and
-                            bs_arch == release_spec.architecture):
+                            bs_arch_family == spec_arch_family):
                             # We found the bootstrap compiler this release spec
                             # should be built with, so for DAG scheduling
                             # purposes, we will at least add the compiler spec
@@ -716,6 +723,15 @@ def generate_gitlab_ci_yaml(env, print_summary, output_file,
                                                  str(bs_arch),
                                                  build_group,
                                                  enable_artifacts_buildcache))
+                        else:
+                            debug_msg = ''.join([
+                                'Considered compiler {0} for spec ',
+                                '{1}, but rejected it either because it was ',
+                                'not the compiler required by the spec, or ',
+                                'because the target arch families of the ',
+                                'spec and the compiler did not match'
+                            ]).format(bs['spec'], release_spec)
+                            tty.debug(debug_msg)
 
                 if enable_cdash_reporting:
                     cdash_build_name = get_cdash_build_name(

lib/spack/spack/test/cmd/ci.py

@@ -195,6 +195,7 @@ def test_ci_generate_bootstrap_gcc(tmpdir, mutable_mock_env_path,
   definitions:
     - bootstrap:
       - gcc@3.0
+      - gcc@2.0
   specs:
     - dyninst%gcc@3.0
   mirrors: