stubtest_third_party: show package versions on failure (#7826)

Co-authored-by: hauntsaninja <>

tests/stubtest_third_party.py

@@ -93,6 +93,10 @@ def run_stubtest(dist: Path) -> bool:
         except subprocess.CalledProcessError:
             print(f"stubtest failed for {dist.name}", file=sys.stderr)
             print("\n\n", file=sys.stderr)
+
+            print("Ran with the following environment:", file=sys.stderr)
+            subprocess.run([pip_exe, "freeze"])
+
             if allowlist_path.exists():
                 print(
                     f'To fix "unused allowlist" errors, remove the corresponding entries from {allowlist_path}', file=sys.stderr