gh-127651: Use __file__ in diagnostics if origin is missing

Lib/test/test_import/__init__.py

@@ -15,6 +15,7 @@
 import os
 import py_compile
 import random
+import re
 import shutil
 import stat
 import subprocess
@@ -812,9 +813,37 @@ def test_frozen_module_from_import_error(self):
             from os import this_will_never_exist
         self.assertRegex(
             str(cm.exception),
-            r"cannot import name 'this_will_never_exist' from 'os' \(.*Lib[\\/]os\.py\)"
+            f"cannot import name 'this_will_never_exist' from 'os' \\({re.escape(os.__file__)}\\)"
         )
 
+
+        scripts = [
+            """
+import os
+os.__spec__.has_location = False
+os.__file__ = 123
+from os import this_will_never_exist
+""",
+            """
+import os
+os.__spec__.has_location = False
+del os.__file__
+from os import this_will_never_exist
+"""
+        ]
+        for script in scripts:
+            with self.subTest(script=script), os_helper.temp_dir() as tmp:
+                with open(os.path.join(tmp, "main.py"), "w", encoding='utf-8') as f:
+                    f.write(script)
+
+                expected_error = (
+                    b"cannot import name 'this_will_never_exist' "
+                    b"from 'os' \\(unknown location\\)"
+                )
+                popen = script_helper.spawn_python(os.path.join(tmp, "main.py"), cwd=tmp)
+                stdout, stderr = popen.communicate()
+                self.assertRegex(stdout, expected_error)
+
     def test_script_shadowing_stdlib(self):
         script_errors = [
             (