Add MacOS and Windows build targets

[StephenBrown2]

Change Summary

As of about a week ago, the cibuildwheel repository has new examples for Travis on Mac and Windows: https://github.com/joerick/cibuildwheel/blob/master/examples/travis-ci-test-and-deploy.yml

This adds those targets to .travis.yml to hopefully resolve #555 .

If this passes (which I can't test myself, since you should handle the releases), I can edit https://github.com/samuelcolvin/pydantic/blob/8727914ced9d4546f0f95a453aff78f03b778275/docs/install.md#L19-L21 to reflect it.

Related issue number

#555

Checklist

• Unit tests for the changes exist
• Tests pass on CI and coverage remains at 100%
• Documentation reflects the changes where applicable
• changes/<pull request or issue id>-<github username>.md file added describing change
  (see changes/README.md for details)

[codecov]

Codecov Report

Merging #1293 into master will increase coverage by 0.00%.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master    #1293   +/-   ##
=======================================
  Coverage   99.89%   99.89%           
=======================================
  Files          21       21           
  Lines        3713     3725   +12     
  Branches      731      736    +5     
=======================================
+ Hits         3709     3721   +12     
  Misses          2        2           
  Partials        2        2           

Impacted Files	Coverage Δ
pydantic/utils.py	98.98% <0.00%> (+0.06%)	⬆️

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[samuelcolvin]

Humm, I'd rather move all this to github actions, see rtoml for a more complex but similar case.

Still until we move to github actions completely, maybe this would be a good stop gap.

[samuelcolvin]

please confirm that these steps are working by commenting out the if: type = push AND (branch = master OR tag IS present) and deploy: chunks.

[StephenBrown2]

Well, MacOS is building, but I can't figure out the Windows errors at the moment. I will happily leave those commented out for someone else to tackle, if you wish.

[demospace]

Well, MacOS is building, but I can't figure out the Windows errors at the moment. I will happily leave those commented out for someone else to tackle, if you wish.

I patched pydantic in a few places recently and tried to compile in Windows and ran into the following:

\temp.win-amd64-3.7\Release\pydantic\__init__.cp37-win_amd64.lib
LINK : error LNK2001: unresolved external symbol PyInit___init__
build\temp.win-amd64-3.7\Release\pydantic\__init__.cp37-win_amd64.lib : fatal error LNK1120: 1 unresolved externals
error: command 'C:\\Program Files (x86)\\Microsoft Visual Studio\\2017\\BuildTools\\VC\\Tools\\MSVC\\14.16.27023\\bin\\HostX86\\x64\\link.exe' failed with exit status 1120

The issue relates to distutils/setuptools and you can read more about it here:
https://bugs.python.org/issue35893
https://stackoverflow.com/questions/58797673/how-to-compile-init-py-file-using-cython-on-window?answertab=votes#tab-top

The SO answer is best. Adding the following to pydantic's setup.py resolves the build on Win32

from distutils.command import build_ext

def get_export_symbols_fixed(self, ext):
    pass

build_ext.get_export_symbols = get_export_symbols_fixed

(a previous version of this post provided the code from the first example which is fragile compared to the solution above)

[StephenBrown2]

In theory this could break non-windows? So best to include it in an os.name check, like:

import os
from distutils.command import build_ext

if os.name == 'nt':

    def pass_ges(self, ext):
        pass

    build_ext.get_export_symbols = pass_ges

[samuelcolvin]

In theory this could break non-windows? So best to include it in an os.name check, like:

import os
from distutils.command import build_ext

if os.name == 'nt':

    def pass_ges(self, ext):
        pass

    build_ext.get_export_symbols = pass_ges

agreed, let's try this.

[StephenBrown2]

Doesn't looke like it's fixed that issue:

  LINK : error LNK2001: unresolved external symbol PyInit___init__

still happening. https://travis-ci.org/github/samuelcolvin/pydantic/jobs/664032568#L228

[StephenBrown2]

Well it looks like that indeed worked. I took the function from cpython master and the patch from the bug report, and Windows builds are now succeeding!

[samuelcolvin]

incorporated into #1326, thank you so much.