pkg.spec.package is pkg after deserialization (#50449)

lib/spack/spack/subprocess_context.py

@@ -17,6 +17,7 @@
 import pickle
 import pydoc
 from types import ModuleType
+from typing import Any
 
 import spack.config
 import spack.environment
@@ -35,11 +36,17 @@ def append_patch(patch):
     patches.append(patch)
 
 
-def serialize(obj):
-    serialized_obj = io.BytesIO()
-    pickle.dump(obj, serialized_obj)
-    serialized_obj.seek(0)
-    return serialized_obj
+def serialize(pkg) -> io.BytesIO:
+    serialized_pkg = io.BytesIO()
+    pickle.dump(pkg, serialized_pkg)
+    serialized_pkg.seek(0)
+    return serialized_pkg
+
+
+def deserialize(serialized_pkg: io.BytesIO) -> Any:
+    pkg = pickle.load(serialized_pkg)
+    pkg.spec._package = pkg
+    return pkg
 
 
 class SpackTestProcess:
@@ -87,8 +94,7 @@ def restore(self):
 
         # Order of operation is important, since the package might be retrieved
         # from a repo defined within the environment configuration
-        pkg = pickle.load(self.serialized_pkg) if self.serialize else self.pkg
-        return pkg
+        return deserialize(self.serialized_pkg) if self.serialize else self.pkg
 
 
 class GlobalStateMarshaler:

lib/spack/spack/test/package_class.py

@@ -24,6 +24,7 @@
 import spack.package_base
 import spack.spec
 import spack.store
+import spack.subprocess_context
 from spack.build_systems.generic import Package
 from spack.error import InstallError
 from spack.solver.input_analysis import NoStaticAnalysis, StaticAnalysis
@@ -323,3 +324,11 @@ def test_package_subscript(default_mock_concretization):
     # Subscript on concrete
     for d in root.traverse():
         assert isinstance(root_pkg[d.name], spack.package_base.PackageBase)
+
+
+def test_deserialize_preserves_package_attribute(default_mock_concretization):
+    x = default_mock_concretization("mpileaks").package
+    assert x.spec._package is x
+
+    y = spack.subprocess_context.deserialize(spack.subprocess_context.serialize(x))
+    assert y.spec._package is y