bpo-41490: Update ensurepip to install pip 20.2.1 and setuptools 49.2.1

[zooba]

https://bugs.python.org/issue41490

[bedevere-bot]

GH-21774 is a backport of this pull request to the 3.9 branch.

[bedevere-bot]

GH-21775 is a backport of this pull request to the 3.8 branch.

[vstinner]

The Travis CI job was blocked, so I closed/reopened the PR to see if it is enough to be able to merge the PR.

[vstinner]

Good: Travis CI job ran this time.

Bad: this PR is affected by https://bugs.python.org/issue41762

[vstinner]

New close/reopen to re-run all CI jobs, to see if it magically solves https://bugs.python.org/issue41762

[vstinner]

Tests / Windows (x86)

FAIL: test_with_pip (test.test_venv.EnsurePipTest)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "D:\a\cpython\cpython\lib\test\test_venv.py", line 476, in do_test_with_pip
    self.run_with_capture(venv.create, self.env_dir,
  File "D:\a\cpython\cpython\lib\test\test_venv.py", line 76, in run_with_capture
    func(*args, **kwargs)
subprocess.CalledProcessError: Command '['C:\\Users\\runneradmin\\AppData\\Local\\Temp\\tmp1ihg5wsq\\Scripts\\python.exe', '-Im', 'ensurepip', '--upgrade', '--default-pip']' returned non-zero exit status 1.

(...)

Traceback (most recent call last):
  File "D:\a\cpython\cpython\lib\shutil.py", line 613, in _rmtree_unsaf
    os.unlink(fullname)
PermissionError: [WinError 32] The process cannot access the file because it is being used by another process: 'C:\\Users\\RUNNER~1\\AppData\\Local\\Temp\\tmpeu5ljzar\\pip-20.2.1-py2.py3-none-any.whl'

Other tests failed:

2 tests failed:
    test_importlib test_venv

4 re-run tests:
    test__xxsubinterpreters test_asyncio test_importlib test_venv

importlib failure:

0:06:59 load avg: 2.78 [245/423/2] test_bigmem passed -- running: test_largefile (3 min 27 sec), test_peg_generator (38.6 sec), test_io (3 min 11 sec)
Failed to import test module: test.test_importlib.test_resource
Traceback (most recent call last):
  File "D:\a\cpython\cpython\lib\unittest\loader.py", line 436, in _find_test_path
    module = self._get_module_from_name(name)
  File "D:\a\cpython\cpython\lib\unittest\loader.py", line 377, in _get_module_from_name
    __import__(name)
  File "D:\a\cpython\cpython\lib\test\test_importlib\test_resource.py", line 10, in <module>
    from test.support import import_helper, unlink
ImportError: cannot import name 'unlink' from 'test.support' (D:\a\cpython\cpython\lib\test\support\__init__.py)

test test_importlib crashed -- Traceback (most recent call last):
  File "D:\a\cpython\cpython\lib\test\libregrtest\runtest.py", line 272, in _runtest_inner
    refleak = _runtest_inner2(ns, test_name)
  File "D:\a\cpython\cpython\lib\test\libregrtest\runtest.py", line 236, in _runtest_inner2
    test_runner()
  File "D:\a\cpython\cpython\lib\test\libregrtest\runtest.py", line 210, in _test_module
    raise Exception("errors while loading tests")
0:07:00 load avg: 2.78 [246/423/3] test_importlib failed -- running: test_largefile (3 min 27 sec), test_peg_generator (39.2 sec), test_io (3 min 11 sec)
Exception: errors while loading tests

[vstinner]

unlink should now be imported from test.support.os_helper.

[ambv]

Note: this should be merged ASAP since the "backports" were.

[vstinner]

New close/reopen attempt to fix the CI.

[vstinner]

Note: this should be merged ASAP since the "backports" were.

I wrote PR #22281 to fix https://bugs.python.org/issue41762 but my current PR is not correct (breaks the rendered documentation).

[vstinner]

I fixed https://bugs.python.org/issue41762 Let me try to close/reopen the issue to see if it's enough to run CI tests on a rebased PR.

[vstinner]

@zooba: Since https://bugs.python.org/issue41762 is now fixed, can you please update Lib/test/test_importlib/test_resource.py? See my previous comment:

unlink should now be imported from test.support.os_helper.

[pablogsal]

You probably want to rebase this on top of #22527 (an drop the pip version bump).

[zooba]

Starting a fresh PR - apologies for the noise.