Python 3.7, Windows: FAIL: with_outer_raising (pure_doctest__generators_py)

[matthew-brett]

A single test error when trying to generate Cython 0.28.3 Windows wheels for Python 3.7:

======================================================================
FAIL: with_outer_raising (pure_doctest__generators_py)
Doctest: pure_doctest__generators_py.with_outer_raising
----------------------------------------------------------------------
Traceback (most recent call last):
  File "C:\Python37\lib\doctest.py", line 2198, in runTest
    raise self.failureException(self.format_failure(new.getvalue()))
AssertionError: Failed doctest test for pure_doctest__generators_py.with_outer_raising
  File "C:\projects\cython-wheels\Cython\tests\run\generators_py.py", line 84, in with_outer_raising
----------------------------------------------------------------------
File "C:\projects\cython-wheels\Cython\tests\run\generators_py.py", line 87, in pure_doctest__generators_py.with_outer_raising
Failed example:
    list(x())
Exception raised:
    Traceback (most recent call last):
      File "C:\projects\cython-wheels\Cython\tests\run\generators_py.py", line 93, in generator
        raise StopIteration
    StopIteration
    The above exception was the direct cause of the following exception:
    Traceback (most recent call last):
      File "C:\Python37\lib\doctest.py", line 1329, in __run
        compileflags, 1), test.globs)
      File "<doctest pure_doctest__generators_py.with_outer_raising[1]>", line 1, in <module>
        list(x())
    RuntimeError: generator raised StopIteration

https://ci.appveyor.com/project/matthew-brett/cython-wheels/build/job/hw0umryi37mobb67#L18595

[matthew-brett]

Sorry - goofed, was previously testing 0.27.3. But same errors for 0.28.3 : https://ci.appveyor.com/project/matthew-brett/cython-wheels/build/job/gmc5wc70ngfcqe83

[jrtc27]

This affects any platform using Python 3.7 and is a result of PEP 479, which changes the default behaviour as of 3.7. Since the from itertools import allow_implicit_stop part of the proposal was rejected, I can't see a way to request the old behaviour, so I suggest this test is simply dropped.

[scoder]

I guess the quick-fix is really to ignore that error or remove the test.

However, since the test only fails in CPython and not in Cython, it's Cython that should follow CPython's behaviour here. (And the test should be fixed in that direction.)

[scoder]

Test fixed here: eae3776
I created a follow-up ticket for the behavioural change: #2580