zipfile module unconditionally requires threading module since revision 4973ccd46e32 (in Python >=3.5), which causes errors in over 50 Lib/test/test_*.py files.


[  1/399] test_cmd_line
test test_cmd_line crashed -- Traceback (most recent call last):
  File "/tmp/cpython/Lib/test/libregrtest/runtest.py", line 149, in runtest_inner
    the_module = importlib.import_module(abstest)
  File "/tmp/cpython/Lib/importlib/__init__.py", line 126, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "<frozen importlib._bootstrap>", line 986, in _gcd_import
  File "<frozen importlib._bootstrap>", line 969, in _find_and_load
  File "<frozen importlib._bootstrap>", line 958, in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 673, in _load_unlocked
  File "<frozen importlib._bootstrap_external>", line 654, in exec_module
  File "<frozen importlib._bootstrap>", line 222, in _call_with_frames_removed
  File "/tmp/cpython/Lib/test/test_cmd_line.py", line 11, in <module>
    from test.support import script_helper
  File "/tmp/cpython/Lib/test/support/script_helper.py", line 14, in <module>
    import zipfile
  File "/tmp/cpython/Lib/zipfile.py", line 16, in <module>
    import threading
  File "/tmp/cpython/Lib/threading.py", line 4, in <module>
    import _thread
ImportError: No module named '_thread'