Add intel-oneapi-runtime, allow injecting virtual dependencies (#42062)

This PR adds:
- A new runtime for `%oneapi` compilers, called `intel-oneapi-runtime`
- Information to both `gcc-runtime`  and `intel-oneapi-runtime`, to ensure
  that we don't mix compilers using different soname for either `libgfortran`
  or `libifcore`

To do so, the following internal mechanisms have been implemented:
- Possibility to inject virtual dependencies from the `runtime_constraints`
  callback on packages

Information has been added to `gcc-runtime` to provide the correct soname
under different conditions on its `%gcc`.

Rules injected into the solver looks like:

```prolog
% Add a dependency on 'gfortran@5' for nodes compiled with gcc@=13.2.0 and using the 'fortran' language
attr("dependency_holds", node(ID, Package), "gfortran", "link") :-
  attr("node", node(ID, Package)),
  attr("node_compiler", node(ID, Package), "gcc"),
  attr("node_compiler_version", node(ID, Package), "gcc", "13.2.0"),
  not external(node(ID, Package)),
  not runtime(Package),
  attr("language", node(ID, Package), "fortran").

attr("virtual_node", node(RuntimeID, "gfortran")) :-
  attr("depends_on", node(ID, Package), ProviderNode, "link"),
  provider(ProviderNode, node(RuntimeID, "gfortran")),
  attr("node", node(ID, Package)),
  attr("node_compiler", node(ID, Package), "gcc"),
  attr("node_compiler_version", node(ID, Package), "gcc", "13.2.0"),
  not external(node(ID, Package)),
  not runtime(Package),
  attr("language", node(ID, Package), "fortran").

attr("node_version_satisfies", node(RuntimeID, "gfortran"), "5") :-
  attr("depends_on", node(ID, Package), ProviderNode, "link"),
  provider(ProviderNode, node(RuntimeID, "gfortran")),
  attr("node", node(ID, Package)),
  attr("node_compiler", node(ID, Package), "gcc"),
  attr("node_compiler_version", node(ID, Package), "gcc", "13.2.0"),
  not external(node(ID, Package)),
  not runtime(Package),
  attr("language", node(ID, Package), "fortran").
```

etc/spack/defaults/packages.yaml

@@ -24,6 +24,7 @@ packages:
       elf: [elfutils]
       fftw-api: [fftw, amdfftw]
       flame: [libflame, amdlibflame]
+      fortran-rt: [gcc-runtime, intel-oneapi-runtime]
       fuse: [libfuse]
       gl: [glx, osmesa]
       glu: [mesa-glu, openglu]
@@ -34,7 +35,9 @@ packages:
       java: [openjdk, jdk, ibm-java]
       jpeg: [libjpeg-turbo, libjpeg]
       lapack: [openblas, amdlibflame]
+      libgfortran: [ gcc-runtime ]
       libglx: [mesa+glx, mesa18+glx]
+      libifcore: [ intel-oneapi-runtime ]
       libllvm: [llvm]
       libosmesa: [mesa+osmesa, mesa18+osmesa]
       lua-lang: [lua, lua-luajit-openresty, lua-luajit]

lib/spack/spack/directives.py

@@ -94,6 +94,9 @@ class OpenMpi(Package):
 PatchesType = Optional[Union[Patcher, str, List[Union[Patcher, str]]]]
 
 
+SUPPORTED_LANGUAGES = ("fortran", "cxx")
+
+
 def _make_when_spec(value: WhenType) -> Optional["spack.spec.Spec"]:
     """Create a ``Spec`` that indicates when a directive should be applied.
 
@@ -585,6 +588,9 @@ def depends_on(
     @see The section "Dependency specs" in the Spack Packaging Guide.
 
     """
+    if spack.spec.Spec(spec).name in SUPPORTED_LANGUAGES:
+        assert type == "build", "languages must be of 'build' type"
+        return _language(lang_spec_str=spec, when=when)
 
     def _execute_depends_on(pkg: "spack.package_base.PackageBase"):
         _depends_on(pkg, spec, when=when, type=type, patches=patches)
@@ -967,7 +973,6 @@ def license(
         checked_by: string or list of strings indicating which github user checked the
             license (if any).
         when: A spec specifying when the license applies.
-            when: A spec specifying when the license applies.
     """
 
     return lambda pkg: _execute_license(pkg, license_identifier, when)
@@ -1014,6 +1019,21 @@ def _execute_requires(pkg: "spack.package_base.PackageBase"):
     return _execute_requires
 
 
+@directive("languages")
+def _language(lang_spec_str: str, *, when: Optional[Union[str, bool]] = None):
+    """Temporary implementation of language virtuals, until compilers are proper dependencies."""
+
+    def _execute_languages(pkg: "spack.package_base.PackageBase"):
+        when_spec = _make_when_spec(when)
+        if not when_spec:
+            return
+
+        languages = pkg.languages.setdefault(when_spec, set())
+        languages.add(lang_spec_str)
+
+    return _execute_languages
+
+
 class DirectiveError(spack.error.SpackError):
     """This is raised when something is wrong with a package directive."""
 

lib/spack/spack/package_base.py

@@ -567,6 +567,7 @@ class PackageBase(WindowsRPath, PackageViewMixin, metaclass=PackageMeta):
     provided_together: Dict["spack.spec.Spec", List[Set[str]]]
     patches: Dict["spack.spec.Spec", List["spack.patch.Patch"]]
     variants: Dict[str, Tuple["spack.variant.Variant", "spack.spec.Spec"]]
+    languages: Dict["spack.spec.Spec", Set[str]]
 
     #: By default, packages are not virtual
     #: Virtual packages override this attribute

lib/spack/spack/solver/asp.py

@@ -1040,6 +1040,16 @@ def conflict_rules(self, pkg):
                 )
                 self.gen.newline()
 
+    def package_languages(self, pkg):
+        for when_spec, languages in pkg.languages.items():
+            condition_msg = f"{pkg.name} needs the {', '.join(sorted(languages))} language"
+            if when_spec != spack.spec.Spec():
+                condition_msg += f" when {when_spec}"
+            condition_id = self.condition(when_spec, name=pkg.name, msg=condition_msg)
+            for language in sorted(languages):
+                self.gen.fact(fn.pkg_fact(pkg.name, fn.language(condition_id, language)))
+        self.gen.newline()
+
     def compiler_facts(self):
         """Facts about available compilers."""
 
@@ -1089,6 +1099,9 @@ def pkg_rules(self, pkg, tests):
         self.pkg_version_rules(pkg)
         self.gen.newline()
 
+        # languages
+        self.package_languages(pkg)
+
         # variants
         self.variant_rules(pkg)
 
@@ -2294,8 +2307,6 @@ def setup(
         self.possible_virtuals = node_counter.possible_virtuals()
         self.pkgs = node_counter.possible_dependencies()
 
-        self.pkgs.update(spack.repo.PATH.packages_with_tags("runtime"))
-
         # Fail if we already know an unreachable node is requested
         for spec in specs:
             missing_deps = [
@@ -2309,7 +2320,6 @@ def setup(
                 self.explicitly_required_namespaces[node.name] = node.namespace
 
         self.gen = ProblemInstanceBuilder()
-
         if not allow_deprecated:
             self.gen.fact(fn.deprecated_versions_not_allowed())
 
@@ -2439,14 +2449,14 @@ def define_runtime_constraints(self):
         """Define the constraints to be imposed on the runtimes"""
         recorder = RuntimePropertyRecorder(self)
         for compiler in self.possible_compilers:
-            if compiler.name != "gcc":
+            compiler_with_different_cls_names = {"oneapi": "intel-oneapi-compilers"}
-                continue
+            compiler_cls_name = compiler_with_different_cls_names.get(compiler.name, compiler.name)
             try:
-                compiler_cls = spack.repo.PATH.get_pkg_class(compiler.name)
+                compiler_cls = spack.repo.PATH.get_pkg_class(compiler_cls_name)
             except spack.repo.UnknownPackageError:
                 continue
             if hasattr(compiler_cls, "runtime_constraints"):
-                compiler_cls.runtime_constraints(compiler=compiler, pkg=recorder)
+                compiler_cls.runtime_constraints(spec=compiler.spec, pkg=recorder)
 
         recorder.consume_facts()
 
@@ -2858,13 +2868,24 @@ def reset(self):
         """Resets the current state."""
         self.current_package = None
 
-    def depends_on(self, dependency_str: str, *, when: str, type: str, description: str) -> None:
+    def depends_on(
+        self,
+        dependency_str: str,
+        *,
+        when: str,
+        type: str,
+        description: str,
+        languages: Optional[List[str]] = None,
+    ) -> None:
         """Injects conditional dependencies on packages.
 
+        Conditional dependencies can be either "real" packages or virtual dependencies.
+
         Args:
             dependency_str: the dependency spec to inject
             when: anonymous condition to be met on a package to have the dependency
             type: dependency type
+            languages: languages needed by the package for the dependency to be considered
             description: human-readable description of the rule for adding the dependency
         """
         # TODO: The API for this function is not final, and is still subject to change. At
@@ -2890,26 +2911,45 @@ def depends_on(self, dependency_str: str, *, when: str, type: str, description:
             f"  not external({node_variable}),\n"
             f"  not runtime(Package)"
         ).replace(f'"{placeholder}"', f"{node_variable}")
+        if languages:
+            body_str += ",\n"
+            for language in languages:
+                body_str += f'  attr("language", {node_variable}, "{language}")'
+
         head_clauses = self._setup.spec_clauses(dependency_spec, body=False)
 
         runtime_pkg = dependency_spec.name
+
+        is_virtual = head_clauses[0].args[0] == "virtual_node"
         main_rule = (
             f"% {description}\n"
             f'1 {{ attr("depends_on", {node_variable}, node(0..X-1, "{runtime_pkg}"), "{type}") :'
-            f' max_dupes("gcc-runtime", X)}} 1:-\n'
+            f' max_dupes("{runtime_pkg}", X)}} 1:-\n'
             f"{body_str}.\n\n"
         )
+        if is_virtual:
+            main_rule = (
+                f"% {description}\n"
+                f'attr("dependency_holds", {node_variable}, "{runtime_pkg}", "{type}") :-\n'
+                f"{body_str}.\n\n"
+            )
+
         self.rules.append(main_rule)
         for clause in head_clauses:
             if clause.args[0] == "node":
                 continue
             runtime_node = f'node(RuntimeID, "{runtime_pkg}")'
             head_str = str(clause).replace(f'"{runtime_pkg}"', runtime_node)
-            rule = (
+            depends_on_constraint = (
-                f"{head_str} :-\n"
                 f'  attr("depends_on", {node_variable}, {runtime_node}, "{type}"),\n'
-                f"{body_str}.\n\n"
             )
+            if is_virtual:
+                depends_on_constraint = (
+                    f'  attr("depends_on", {node_variable}, ProviderNode, "{type}"),\n'
+                    f"  provider(ProviderNode, {runtime_node}),\n"
+                )
+
+            rule = f"{head_str} :-\n" f"{depends_on_constraint}" f"{body_str}.\n\n"
             self.rules.append(rule)
 
         self.reset()

lib/spack/spack/solver/concretize.lp

@@ -158,6 +158,14 @@ error(100, multiple_values_error, Attribute, Package)
      attr_single_value(Attribute),
      2 { attr(Attribute, node(ID, Package), Value) }.
 
+%-----------------------------------------------------------------------------
+% Languages used
+%-----------------------------------------------------------------------------
+
+attr("language", node(X, Package), Language) :-
+  condition_holds(ConditionID, node(X, Package)),
+  pkg_fact(Package,language(ConditionID, Language)).
+
 %-----------------------------------------------------------------------------
 % Version semantics
 %-----------------------------------------------------------------------------

lib/spack/spack/solver/counter.py

@@ -10,6 +10,7 @@
 import spack.deptypes as dt
 import spack.package_base
 import spack.repo
+import spack.spec
 
 PossibleDependencies = Set[str]
 
@@ -24,7 +25,13 @@ class Counter:
     """
 
     def __init__(self, specs: List["spack.spec.Spec"], tests: bool) -> None:
-        self.specs = specs
+        runtime_pkgs = spack.repo.PATH.packages_with_tags("runtime")
+        runtime_virtuals = set()
+        for x in runtime_pkgs:
+            pkg_class = spack.repo.PATH.get_pkg_class(x)
+            runtime_virtuals.update(pkg_class.provided_virtual_names())
+
+        self.specs = specs + [spack.spec.Spec(x) for x in runtime_pkgs]
 
         self.link_run_types: dt.DepFlag = dt.LINK | dt.RUN | dt.TEST
         self.all_types: dt.DepFlag = dt.ALL
@@ -33,7 +40,9 @@ def __init__(self, specs: List["spack.spec.Spec"], tests: bool) -> None:
             self.all_types = dt.LINK | dt.RUN | dt.BUILD
 
         self._possible_dependencies: PossibleDependencies = set()
-        self._possible_virtuals: Set[str] = set(x.name for x in specs if x.virtual)
+        self._possible_virtuals: Set[str] = (
+            set(x.name for x in specs if x.virtual) | runtime_virtuals
+        )
 
     def possible_dependencies(self) -> PossibleDependencies:
         """Returns the list of possible dependencies"""

var/spack/repos/builtin/packages/gcc-runtime/package.py

@@ -22,6 +22,9 @@ class GccRuntime(Package):
 
     tags = ["runtime"]
 
+    # gcc-runtime versions are declared dynamically
+    skip_version_audit = ["platform=linux", "platform=darwin"]
+
     maintainers("haampie")
 
     license("GPL-3.0-or-later WITH GCC-exception-3.1")
@@ -44,9 +47,15 @@ class GccRuntime(Package):
         "ubsan",
     ]
 
+    # libgfortran ABI
+    provides("fortran-rt", "libgfortran")
+    provides("libgfortran@3", when="%gcc@:6")
+    provides("libgfortran@4", when="%gcc@7")
+    provides("libgfortran@5", when="%gcc@8:")
+
     def install(self, spec, prefix):
         if spec.platform in ["linux", "cray", "freebsd"]:
-            libraries = self._get_libraries_elf()
+            libraries = get_elf_libraries(compiler=self.compiler, libraries=self.LIBRARIES)
         elif spec.platform == "darwin":
             libraries = self._get_libraries_macho()
         else:
@@ -61,47 +70,6 @@ def install(self, spec, prefix):
         for path, name in libraries:
             install(path, os.path.join(prefix.lib, name))
 
-    def _get_libraries_elf(self):
-        """Get the GCC runtime libraries for ELF binaries"""
-        cc = Executable(self.compiler.cc)
-        lib_regex = re.compile(rb"\blib[a-z-_]+\.so\.\d+\b")
-        path_and_install_name = []
-
-        for name in self.LIBRARIES:
-            # Look for the dynamic library that gcc would use to link,
-            # that is with .so extension and without abi suffix.
-            path = cc(f"-print-file-name=lib{name}.so", output=str).strip()
-
-            # gcc reports an absolute path on success
-            if not os.path.isabs(path):
-                continue
-
-            # Now there are two options:
-            # 1. the file is an ELF file
-            # 2. the file is a linker script referencing the actual library
-            with open(path, "rb") as f:
-                try:
-                    # Try to parse as an ELF file
-                    soname = parse_elf(f, dynamic_section=True).dt_soname_str.decode("utf-8")
-                except Exception:
-                    # On failure try to "parse" as ld script; the actual
-                    # library needs to be mentioned by filename.
-                    f.seek(0)
-                    script_matches = lib_regex.findall(f.read())
-                    if len(script_matches) != 1:
-                        continue
-                    soname = script_matches[0].decode("utf-8")
-
-            # Now locate and install the runtime library
-            runtime_path = cc(f"-print-file-name={soname}", output=str).strip()
-
-            if not os.path.isabs(runtime_path):
-                continue
-
-            path_and_install_name.append((runtime_path, soname))
-
-        return path_and_install_name
-
     def _get_libraries_macho(self):
         """Same as _get_libraries_elf but for Mach-O binaries"""
         cc = Executable(self.compiler.cc)
@@ -152,3 +120,45 @@ def libs(self):
     @property
     def headers(self):
         return HeaderList([])
+
+
+def get_elf_libraries(compiler, libraries):
+    """Get the GCC runtime libraries for ELF binaries"""
+    cc = Executable(compiler.cc)
+    lib_regex = re.compile(rb"\blib[a-z-_]+\.so\.\d+\b")
+    path_and_install_name = []
+
+    for name in libraries:
+        # Look for the dynamic library that gcc would use to link,
+        # that is with .so extension and without abi suffix.
+        path = cc(f"-print-file-name=lib{name}.so", output=str).strip()
+
+        # gcc reports an absolute path on success
+        if not os.path.isabs(path):
+            continue
+
+        # Now there are two options:
+        # 1. the file is an ELF file
+        # 2. the file is a linker script referencing the actual library
+        with open(path, "rb") as f:
+            try:
+                # Try to parse as an ELF file
+                soname = parse_elf(f, dynamic_section=True).dt_soname_str.decode("utf-8")
+            except Exception:
+                # On failure try to "parse" as ld script; the actual
+                # library needs to be mentioned by filename.
+                f.seek(0)
+                script_matches = lib_regex.findall(f.read())
+                if len(script_matches) != 1:
+                    continue
+                soname = script_matches[0].decode("utf-8")
+
+        # Now locate and install the runtime library
+        runtime_path = cc(f"-print-file-name={soname}", output=str).strip()
+
+        if not os.path.isabs(runtime_path):
+            continue
+
+        path_and_install_name.append((runtime_path, soname))
+
+    return path_and_install_name

var/spack/repos/builtin/packages/gcc/package.py

@@ -1144,7 +1144,7 @@ def detect_gdc(self):
                 )
 
     @classmethod
-    def runtime_constraints(cls, *, compiler, pkg):
+    def runtime_constraints(cls, *, spec, pkg):
         """Callback function to inject runtime-related rules into the solver.
 
         Rule-injection is obtained through method calls of the ``pkg`` argument.
@@ -1153,7 +1153,7 @@ def runtime_constraints(cls, *, compiler, pkg):
         we'll document the behavior at https://spack.readthedocs.io/en/latest/
 
         Args:
-            compiler: compiler object (node attribute) currently considered
+            spec: spec that will inject runtime dependencies
             pkg: object used to forward information to the solver
         """
         pkg("*").depends_on(
@@ -1163,11 +1163,27 @@ def runtime_constraints(cls, *, compiler, pkg):
             description="If any package uses %gcc, it depends on gcc-runtime",
         )
         pkg("*").depends_on(
-            f"gcc-runtime@{str(compiler.version)}:",
+            f"gcc-runtime@{str(spec.version)}:",
-            when=f"%{str(compiler.spec)}",
+            when=f"%{str(spec)}",
             type="link",
-            description=f"If any package uses %{str(compiler.spec)}, "
+            description=f"If any package uses %{str(spec)}, "
-            f"it depends on gcc-runtime@{str(compiler.version)}:",
+            f"it depends on gcc-runtime@{str(spec.version)}:",
         )
+
+        gfortran_str = "libgfortran@5"
+        if spec.satisfies("gcc@:6"):
+            gfortran_str = "libgfortran@3"
+        elif spec.satisfies("gcc@7"):
+            gfortran_str = "libgfortran@4"
+
+        for fortran_virtual in ("fortran-rt", gfortran_str):
+            pkg("*").depends_on(
+                fortran_virtual,
+                when=f"%{str(spec)}",
+                languages=["fortran"],
+                type="link",
+                description=f"Add a dependency on '{gfortran_str}' for nodes compiled with "
+                f"{str(spec)} and using the 'fortran' language",
+            )
         # The version of gcc-runtime is the same as the %gcc used to "compile" it
-        pkg("gcc-runtime").requires(f"@={str(compiler.version)}", when=f"%{str(compiler.spec)}")
+        pkg("gcc-runtime").requires(f"@={str(spec.version)}", when=f"%{str(spec)}")

var/spack/repos/builtin/packages/hdf5/package.py

@@ -33,6 +33,9 @@ class Hdf5(CMakePackage):
 
     license("custom")
 
+    depends_on("cxx", type="build", when="+cxx")
+    depends_on("fortran", type="build", when="+fortran")
+
     # The 'develop' version is renamed so that we could uninstall (or patch) it
     # without affecting other develop version.
     version("develop-1.15", branch="develop")

var/spack/repos/builtin/packages/intel-oneapi-compilers/package.py

@@ -388,3 +388,31 @@ def _ld_library_path(self):
             p = join_path(self.component_prefix.linux, d)
             if find(p, "*." + dso_suffix, recursive=False):
                 yield p
+
+    @classmethod
+    def runtime_constraints(cls, *, spec, pkg):
+        pkg("*").depends_on(
+            "intel-oneapi-runtime",
+            when="%oneapi",
+            type="link",
+            description="If any package uses %oneapi, it depends on intel-oneapi-runtime",
+        )
+        pkg("*").depends_on(
+            f"intel-oneapi-runtime@{str(spec.version)}:",
+            when=f"%{str(spec)}",
+            type="link",
+            description=f"If any package uses %{str(spec)}, "
+            f"it depends on intel-oneapi-runtime@{str(spec.version)}:",
+        )
+
+        for fortran_virtual in ("fortran-rt", "libifcore@5"):
+            pkg("*").depends_on(
+                fortran_virtual,
+                when=f"%{str(spec)}",
+                languages=["fortran"],
+                type="link",
+                description=f"Add a dependency on 'libifcore' for nodes compiled with "
+                f"{str(spec)} and using the 'fortran' language",
+            )
+        # The version of gcc-runtime is the same as the %gcc used to "compile" it
+        pkg("intel-oneapi-runtime").requires(f"@={str(spec.version)}", when=f"%{str(spec)}")

var/spack/repos/builtin/packages/intel-oneapi-runtime/package.py

@@ -0,0 +1,61 @@
+# Copyright 2013-2024 Lawrence Livermore National Security, LLC and other
+# Spack Project Developers. See the top-level COPYRIGHT file for details.
+#
+# SPDX-License-Identifier: (Apache-2.0 OR MIT)
+import os
+
+from llnl.util import tty
+
+from spack.package import *
+from spack.pkg.builtin.gcc_runtime import get_elf_libraries
+
+
+class IntelOneapiRuntime(Package):
+    """Package for OneAPI compiler runtime libraries"""
+
+    homepage = "https://software.intel.com/content/www/us/en/develop/tools/oneapi.html"
+    has_code = False
+
+    tags = ["runtime"]
+
+    requires("%oneapi")
+
+    depends_on("gcc-runtime", type="link")
+
+    LIBRARIES = [
+        "imf",
+        "intlc",
+        "irng",
+        "svml",
+        "ifcore",  # Fortran
+        "ifcoremt",  # Fortran
+        "ifport",  # Fortran
+        "iomp5",
+        "sycl",
+    ]
+
+    # libifcore ABI
+    provides("fortran-rt", "libifcore@5", when="%oneapi@2021:")
+    provides("sycl")
+
+    conflicts("platform=windows", msg="IntelOneAPI can only be installed on Linux, and FreeBSD")
+    conflicts("platform=darwin", msg="IntelOneAPI can only be installed on Linux, and FreeBSD")
+
+    def install(self, spec, prefix):
+        libraries = get_elf_libraries(compiler=self.compiler, libraries=self.LIBRARIES)
+        mkdir(prefix.lib)
+
+        if not libraries:
+            tty.warn("Could not detect any shared OneAPI runtime libraries")
+            return
+
+        for path, name in libraries:
+            install(path, os.path.join(prefix.lib, name))
+
+    @property
+    def libs(self):
+        return LibraryList([])
+
+    @property
+    def headers(self):
+        return HeaderList([])

var/spack/repos/compiler_runtime.test/packages/gcc/package.py

@@ -14,7 +14,7 @@ class Gcc(Package):
     version("12.3.0")
 
     @classmethod
-    def runtime_constraints(cls, *, compiler, pkg):
+    def runtime_constraints(cls, *, spec, pkg):
         pkg("*").depends_on(
             "gcc-runtime",
             when="%gcc",
@@ -22,11 +22,11 @@ def runtime_constraints(cls, *, compiler, pkg):
             description="If any package uses %gcc, it depends on gcc-runtime",
         )
         pkg("*").depends_on(
-            f"gcc-runtime@{str(compiler.version)}:",
+            f"gcc-runtime@{str(spec.version)}:",
-            when=f"%{str(compiler.spec)}",
+            when=f"%{str(spec)}",
             type="link",
-            description=f"If any package uses %{str(compiler.spec)}, "
+            description=f"If any package uses %{str(spec)}, "
-            f"it depends on gcc-runtime@{str(compiler.version)}:",
+            f"it depends on gcc-runtime@{str(spec.version)}:",
         )
         # The version of gcc-runtime is the same as the %gcc used to "compile" it
-        pkg("gcc-runtime").requires(f"@={str(compiler.version)}", when=f"%{str(compiler.spec)}")
+        pkg("gcc-runtime").requires(f"@={str(spec.version)}", when=f"%{str(spec)}")