[Python-Dev] Status of C compilers for Python on Windows

[Stephen J. Turnbull]

R. David Murray writes:
 > On Sun, 26 Oct 2014 00:19:44 +0200, Antoine Pitrou <solipsis at pitrou.net> wrote:

 > > My point is that your "Windows build" would not have the same behaviour
 > > as a MSVC-produced Windows build, and so testing it with it would not
 > > certify that your code would actually be compatible with genuine
 > > MSVC builds of CPython, which we will not stop supporting.
 > 
 > While true, I don't think that matters for Chris' point.

[...]

 > If I could use a more linux-like toolchain to build CPython on windows,
 > I would doubtless do much more testing on windows for stuff where I
 > think windows might behave differently (and I might look at more Windows
 > bugs...though frankly there are plenty of bugs for me to look at without
 > looking at Windows bugs).
 > 
 > This is not necessarily a compelling argument for MinGW support.
 > However, it *is* a valid argument, IMO.

Nobody claims that the there are not arguments, even compelling
arguments, for MinGW support (more generally, support for alternative
toolchains).

But there are *also* compelling arguments for *supporting* *both*
those "no need to worry about mixed ABIs" situations and *mixed*
situations.  And that becomes Python Dev's problem if the patches are
added to core Python.  Currently, they're somebody else's problem, and
that's as it should be at this stage.

Python is open source.  Nobody is objecting to "somebody else" doing
this.[1]  The problem here is simply that some "somebody elses" are
trying to throw future work over the wall into python-dev space.
There is nothing wrong with that, either -- that's why there is a
stdlib, for example -- but the python-dev concerns about platform
fragmentation are genuine (even if not applicable to all potential
users of the alternative toolchains), and substantial resources will
be needed to do the testing required to meet python-dev's requirement
that such code be *binary* compatible with other binaries downloaded
for Windows, as well as for maintenance of the code itself.


Footnotes: 
[1]  Some *do* question whether there's a need for anybody to do this,
and that's bogus.  "I just wanna" is good enough reason to do it.  The
issue here is that it's not good enough reason for python-dev to do
the support and maintenance going forward.