Cloned master (v3.8) from github. os: Arch x86_64, kernel: 4.14.56-1-lts. successfully ran `./configure --enable-optimizations` and `make`, but failed with this error message when running `make test` 

```
======================================================================
FAIL: test_close_fds (test.test_subprocess.POSIXProcessTestCase)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/asher/sources/cpython3.8/Lib/test/test_subprocess.py", line 2378, in test_close_fds
    "Some fds were left open")
AssertionError: {3} is not false : Some fds were left open

======================================================================
FAIL: test_close_fds_after_preexec (test.test_subprocess.POSIXProcessTestCase)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/asher/sources/cpython3.8/Lib/test/test_subprocess.py", line 2653, in test_close_fds_after_preexec
    self.assertNotIn(fd, remaining_fds)
AssertionError: 3 unexpectedly found in {0, 1, 2, 3}

======================================================================
FAIL: test_pass_fds (test.test_subprocess.POSIXProcessTestCase)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/asher/sources/cpython3.8/Lib/test/support/__init__.py", line 615, in wrapper
    return func(*args, **kw)
  File "/home/asher/sources/cpython3.8/Lib/test/test_subprocess.py", line 2503, in test_pass_fds
    "fd to be closed passed")
AssertionError: {4} is not false : fd to be closed passed

----------------------------------------------------------------------
Ran 285 tests in 23.861s

FAILED (failures=3, skipped=28)
test test_subprocess failed
1 test failed again:
    test_subprocess

== Tests result: FAILURE then FAILURE ==

404 tests OK.

1 test failed:
    test_subprocess

13 tests skipped:
    test_devpoll test_gdb test_kqueue test_msilib test_ossaudiodev
    test_startfile test_tix test_tk test_ttk_guionly test_winconsoleio
    test_winreg test_winsound test_zipfile64

1 re-run test:
    test_subprocess

Total duration: 3 min 59 sec
Tests result: FAILURE then FAILURE
make: *** [Makefile:1058: test] Error 2
```