AppVeyor pre-3.5 tests are failing

[mattsb42-aws]

Figure out why

ex:

https://ci.appveyor.com/project/mattsb42-aws/aws-encryption-sdk-python-qvyet/builds/25075033

[caitlin-tibbetts]

I'll look into this.

[mattsb42-aws]

Update: looks like now all pre-3.5 versions are failing, now for possibly different reasons... :(

ex:
https://ci.appveyor.com/project/mattsb42-aws/aws-encryption-sdk-python-qvyet/builds/26119032

[caitlin-tibbetts]

For Python34, the issue seems to be that the version of the module ast in the Python library that AppVeyor is running to test Python34 does not include the attribute MatMult. This is confirmed in the docs for the version of ast run in 3.4.

Traceback (most recent call last):
  File "c:\python34-x64\Lib\runpy.py", line 170, in _run_module_as_main
    "__main__", mod_spec)
  File "c:\python34-x64\Lib\runpy.py", line 85, in _run_code
    exec(code, run_globals)
  File "C:\projects\aws-encryption-sdk-python-qvyet\.tox\py34-examples\Scripts\pytest.EXE\__main__.py", line 5, in <module>
  File "c:\projects\aws-encryption-sdk-python-qvyet\.tox\py34-examples\lib\site-packages\pytest.py", line 6, in <module>
    from _pytest.assertion import register_assert_rewrite
  File "c:\projects\aws-encryption-sdk-python-qvyet\.tox\py34-examples\lib\site-packages\_pytest\assertion\__init__.py", line 6, in <module>
    from _pytest.assertion import rewrite
  File "c:\projects\aws-encryption-sdk-python-qvyet\.tox\py34-examples\lib\site-packages\_pytest\assertion\rewrite.py", line 443, in <module>
    ast.MatMult: "@",
AttributeError: 'module' object has no attribute 'MatMult'

[caitlin-tibbetts]

The offending code is in c:\projects\aws-encryption-sdk-python-qvyet\.tox\py34-examples\lib\site-packages\_pytest\assertion\rewrite.py

# Python 3.5+ compatibility
try:
    binop_map[ast.MatMult] = "@"
except AttributeError:
    pass

Which does not seem to run because an AttributeError was still raised.

A way to fix this would be to wrap the block in an if-block that makes sure that MatMult exists in ast, but this file is generated in the .tox folder, so it cannot be changed at this stage.

if hasattr(ast, "MatMult"):

[acioc]

Closed stale PR for this issue

[farleyb-amazon]

CI has been fixed, plus we no longer support <3.5. Resolving.