Start a shared utility script for poking around at the import internals

Tools/scripts/import_diagnostics.py

+#!/usr/bin/env python3
+"""Miscellaneous diagnostics for the import system"""
+
+import sys
+import argparse
+from pprint import pprint
+
+def _dump_state(args):
+    print(sys.version)
+    print("sys.path:")
+    pprint(sys.path)
+    print("sys.meta_path")
+    pprint(sys.meta_path)
+    print("sys.path_hooks")
+    pprint(sys.path_hooks)
+    print("sys.path_importer_cache")
+    pprint(sys.path_importer_cache)
+    print("sys.modules:")
+    pprint(sys.modules)
+
+COMMANDS = (
+  ("dump", "Dump import state", _dump_state),
+)
+
+def _make_parser():
+    parser = argparse.ArgumentParser()
+    sub = parser.add_subparsers(title="Commands")
+    for name, description, implementation in COMMANDS:
+        cmd = sub.add_parser(name, help=description)
+        cmd.set_defaults(command=implementation)
+    return parser
+
+def main(args):
+    parser = _make_parser()
+    args = parser.parse_args(args)
+    return args.command(args)
+
+if __name__ == "__main__":
+    sys.exit(main(sys.argv[1:]))