package hash: resolve package by namespace (spack#52777)

The package hash of a spec is supposed to describe the package.py it is
concretized
with, but both lookups that produce it went by name instead of fullname.

Signed-off-by: Harmen Stoppels <me@harmenstoppels.nl>

Author: haampie

lib/spack/spack/hash_types.py

@@ -56,7 +56,7 @@ def __repr__(self) -> str:
 
 
 def _content_hash_override(spec: "spack.spec.Spec") -> str:
-    pkg_cls = spack.repo.PATH.get_pkg_class(spec.name)
+    pkg_cls = spack.repo.PATH.get_pkg_class(spec.fullname)
     pkg = pkg_cls(spec)
     return pkg.content_hash()
 

lib/spack/spack/test/util/package_hash.py

@@ -10,6 +10,7 @@
 import spack.concretize
 import spack.directives_meta
 import spack.paths
+import spack.repo
 import spack.util.package_hash as ph
 from spack.repo import RepoPath
 from spack.spec import Spec
@@ -116,6 +117,17 @@ def test_content_hash_not_concretized(mock_packages: RepoPath, config):
     compare_hash_sans_name(mock_packages, False, spec1, spec2)
 
 
+def test_package_hash_of_shadowed_package(mock_packages: RepoPath, config, repo_builder):
+    """The package hash must describe the package.py of the repository the spec names, also when
+    a repository of higher precedence has a package of the same name."""
+    repo_builder.add_package("pkg-c")
+    with spack.repo.use_repositories(repo_builder.root, override=False):
+        shadowing = Spec(f"{repo_builder.namespace}.pkg-c")
+        shadowed = Spec("builtin_mock.pkg-c")
+
+        assert ph.package_hash(shadowing) != ph.package_hash(shadowed)
+
+
 def test_content_hash_different_variants(mock_packages: RepoPath, config):
     spec1 = spack.concretize.concretize_one("hash-test1@1.2 +variantx")
     spec2 = spack.concretize.concretize_one("hash-test2@1.2 ~variantx")

lib/spack/spack/util/package_hash.py

@@ -372,7 +372,7 @@ def package_ast(
         source: Optionally provide a string to read python code from.
     """
     if source is None:
-        filename = spack.repo.PATH.filename_for_package_name(spec.name)
+        filename = spack.repo.PATH.filename_for_package_name(spec.fullname)
         with open(filename, "rb") as f:
             source = f.read()