bug#26286: python-pexpect 4.2.1 test failure in test_async_utf8

[Danny Milosavljevic]

python-pexpect 4.2.1 has a test failure on both master and core-updates:

.E................................................/gnu/store/cn670s29lsf2nr5axd8gmhl8sb9qpyiq-which-2.21/bin/which:
 no g77 in (/tmp/guix-build-python-pexpect-4.2.1.drv-0/tmpywfead93)
/gnu/store/cn670s29lsf2nr5axd8gmhl8sb9qpyiq-which-2.21/bin/which: no g77 in 
(/tmp/guix-build-python-pexpect-4.2.1.drv-0/tmpywfead93)
/gnu/store/cn670s29lsf2nr5axd8gmhl8sb9qpyiq-which-2.21/bin/which: no g77 in 
(/tmp/guix-build-python-pexpect-4.2.1.drv-0/tmpywfead93)

/gnu/store/cn670s29lsf2nr5axd8gmhl8sb9qpyiq-which-2.21/bin/which: no g77 in 
(/tmp/guix-build-python-pexpect-4.2.1.drv-0/tmpywfead93)
/gnu/store/cn670s29lsf2nr5axd8gmhl8sb9qpyiq-which-2.21/bin/which: no g77 in 
(/tmp/guix-build-python-pexpect-4.2.1.drv-0/tmpywfead93)
/gnu/store/cn670s29lsf2nr5axd8gmhl8sb9qpyiq-which-2.21/bin/which: no g77 in 
(/tmp/guix-build-python-pexpect-4.2.1.drv-0/tmpywfead93)
/gnu/store/cn670s29lsf2nr5axd8gmhl8sb9qpyiq-which-2.21/bin/which: no g77 in 
(/tmp/guix-build-python-pexpect-4.2.1.drv-0/tmpywfead93)
/gnu/store/cn670s29lsf2nr5axd8gmhl8sb9qpyiq-which-2.21/bin/which: no g77 in 
(/tmp/guix-build-python-pexpect-4.2.1.drv-0/tmpywfead93)

/gnu/store/cn670s29lsf2nr5axd8gmhl8sb9qpyiq-which-2.21/bin/which: no g77 in 
(/tmp/guix-build-python-pexpect-4.2.1.drv-0/tmpywfead93)
/gnu/store/cn670s29lsf2nr5axd8gmhl8sb9qpyiq-which-2.21/bin/which: no g77 in 
(/tmp/guix-build-python-pexpect-4.2.1.drv-0/tmpywfead93)
/gnu/store/cn670s29lsf2nr5axd8gmhl8sb9qpyiq-which-2.21/bin/which: no g77 in 
(/tmp/guix-build-python-pexpect-4.2.1.drv-0/tmpywfead93)
/gnu/store/cn670s29lsf2nr5axd8gmhl8sb9qpyiq-which-2.21/bin/which: no g77 in 
(/tmp/guix-build-python-pexpect-4.2.1.drv-0/tmpywfead93)
/gnu/store/cn670s29lsf2nr5axd8gmhl8sb9qpyiq-which-2.21/bin/which: no g77 in 
(/tmp/guix-build-python-pexpect-4.2.1.drv-0/tmpywfead93)

/gnu/store/cn670s29lsf2nr5axd8gmhl8sb9qpyiq-which-2.21/bin/which: no g77 in 
(/tmp/guix-build-python-pexpect-4.2.1.drv-0/tmpywfead93)
/gnu/store/cn670s29lsf2nr5axd8gmhl8sb9qpyiq-which-2.21/bin/which: no g77 in 
(/tmp/guix-build-python-pexpect-4.2.1.drv-0/tmpywfead93)
/gnu/store/cn670s29lsf2nr5axd8gmhl8sb9qpyiq-which-2.21/bin/which: no g77 in 
(/tmp/guix-build-python-pexpect-4.2.1.drv-0/tmpywfead93)
/gnu/store/cn670s29lsf2nr5axd8gmhl8sb9qpyiq-which-2.21/bin/which: no g77 in 
(/tmp/guix-build-python-pexpect-4.2.1.drv-0/tmpywfead93)
/gnu/store/cn670s29lsf2nr5axd8gmhl8sb9qpyiq-which-2.21/bin/which: no g77 in 
(/tmp/guix-build-python-pexpect-4.2.1.drv-0/tmpywfead93)

/gnu/store/cn670s29lsf2nr5axd8gmhl8sb9qpyiq-which-2.21/bin/which: no g77 in 
(/tmp/guix-build-python-pexpect-4.2.1.drv-0/tmpywfead93)
/gnu/store/cn670s29lsf2nr5axd8gmhl8sb9qpyiq-which-2.21/bin/which: no g77 in 
(/tmp/guix-build-python-pexpect-4.2.1.drv-0/tmpywfead93)

/gnu/store/cn670s29lsf2nr5axd8gmhl8sb9qpyiq-which-2.21/bin/which: no g77 in 
(/tmp/guix-build-python-pexpect-4.2.1.drv-0/tmpywfead93)
/gnu/store/cn670s29lsf2nr5axd8gmhl8sb9qpyiq-which-2.21/bin/which: no g77 in 
(/tmp/guix-build-python-pexpect-4.2.1.drv-0/tmpywfead93)

/gnu/store/cn670s29lsf2nr5axd8gmhl8sb9qpyiq-which-2.21/bin/which: no g77 in 
(/tmp/guix-build-python-pexpect-4.2.1.drv-0/tmpywfead93)
/gnu/store/cn670s29lsf2nr5axd8gmhl8sb9qpyiq-which-2.21/bin/which: no g77 in 
(/tmp/guix-build-python-pexpect-4.2.1.drv-0/tmpywfead93)

..
======================================================================
ERROR: test_async_utf8 (tests.test_async.AsyncTests)
----------------------------------------------------------------------
Traceback (most recent call last):
  File 
"/tmp/guix-build-python-pexpect-4.2.1.drv-0/pexpect-4.2.1/tests/test_async.py", 
line 57, in test_async_utf8
    assert run(p.expect_exact([u'foo', pexpect.EOF], async=True)) == 1
  File 
"/tmp/guix-build-python-pexpect-4.2.1.drv-0/pexpect-4.2.1/tests/test_async.py", 
line 13, in run
    return asyncio.get_event_loop().run_until_complete(coro)
  File 
"/gnu/store/alk9r3rir93pjmv8im20f8xrvv90219z-python-3.5.2/lib/python3.5/asyncio/base_events.py",
 line 387, in run_until_complete
    return future.result()
  File 
"/gnu/store/alk9r3rir93pjmv8im20f8xrvv90219z-python-3.5.2/lib/python3.5/asyncio/futures.py",
 line 274, in result
    raise self._exception
  File 
"/gnu/store/alk9r3rir93pjmv8im20f8xrvv90219z-python-3.5.2/lib/python3.5/asyncio/tasks.py",
 line 239, in _step
    result = coro.send(None)
  File 
"/tmp/guix-build-python-pexpect-4.2.1.drv-0/pexpect-4.2.1/pexpect/async.py", 
line 17, in expect_async
    .connect_read_pipe(lambda: PatternWaiter(expecter), expecter.spawn)
  File 
"/gnu/store/alk9r3rir93pjmv8im20f8xrvv90219z-python-3.5.2/lib/python3.5/asyncio/base_events.py",
 line 986, in connect_read_pipe
    transport = self._make_read_pipe_transport(pipe, protocol, waiter)
  File 
"/gnu/store/alk9r3rir93pjmv8im20f8xrvv90219z-python-3.5.2/lib/python3.5/asyncio/unix_events.py",
 line 169, in _make_read_pipe_transport
    return _UnixReadPipeTransport(self, pipe, protocol, waiter, extra)
  File 
"/gnu/store/alk9r3rir93pjmv8im20f8xrvv90219z-python-3.5.2/lib/python3.5/asyncio/unix_events.py",
 line 308, in __init__
    mode = os.fstat(self._fileno).st_mode
OSError: [Errno 9] Bad file descriptor
-------------------- >> begin captured stdout << ---------------------

 tests.test_async.AsyncTests.test_async_utf8 
--------------------- >> end captured stdout << ----------------------
-------------------- >> begin captured logging << --------------------
asyncio: DEBUG: Using selector: EpollSelector
--------------------- >> end captured logging << ---------------------

----------------------------------------------------------------------
Ran 52 tests in 23.885s

FAILED (errors=1)
phase `check' failed after 25.2 seconds
note: keeping build directory `/tmp/guix-build-python-pexpect-4.2.1.drv-5'
builder for 
`/gnu/store/8sd3qd624yj6jacki7xajvclwnjwapma-python-pexpect-4.2.1.drv' failed 
with exit code 1
@ build-failed 
/gnu/store/8sd3qd624yj6jacki7xajvclwnjwapma-python-pexpect-4.2.1.drv - 1 
builder for 
`/gnu/store/8sd3qd624yj6jacki7xajvclwnjwapma-python-pexpect-4.2.1.drv' failed 
with exit code 1
guix build: error: build failed: build of 
`/gnu/store/8sd3qd624yj6jacki7xajvclwnjwapma-python-pexpect-4.2.1.drv' failed