tests/pythons: convert to new stand-alone test process (#38340)

lib/spack/spack/build_systems/python.py

@@ -23,6 +23,7 @@
 import spack.store
 from spack.directives import build_system, depends_on, extends, maintainers
 from spack.error import NoHeadersError, NoLibrariesError, SpecError
+from spack.install_test import test_part
 from spack.version import Version
 
 from ._checks import BaseBuilder, execute_install_time_tests
@@ -167,18 +168,20 @@ def remove_files_from_view(self, view, merge_map):
 
         view.remove_files(to_remove)
 
-    def test(self):
+    def test_imports(self):
         """Attempts to import modules of the installed package."""
 
         # Make sure we are importing the installed modules,
         # not the ones in the source directory
+        python = inspect.getmodule(self).python.path
         for module in self.import_modules:
-            self.run_test(
-                inspect.getmodule(self).python.path,
-                ["-c", "import {0}".format(module)],
-                purpose="checking import of {0}".format(module),
+            with test_part(
+                self,
+                f"test_imports_{module}",
+                purpose=f"checking import of {module}",
                 work_dir="spack-test",
-            )
+            ):
+                python("-c", f"import {module}")
 
     def update_external_dependencies(self, extendee_spec=None):
         """