[Python-Dev] Backporting the 3.5+ Windows build project files to 2.7

[Zachary Ware]

On Mon, Jun 22, 2015 at 5:20 PM, Steve Dower <Steve.Dower at microsoft.com> wrote:
> Zachary Ware wrote:
>> With the stipulation that the officially supported compiler won't change, I want
>> to make sure there's no major opposition to replacing the old project files in
>> PCbuild. The old files would move to PC\VS9.0, so they'll still be available and
>> usable if necessary.
>
> I'm selfishly -0, since this won't benefit me and will give me more work (I don't develop 2.7 other than to build the releases, so this will just cause me to mess with my build machine). But since other people are doing most of the work I'm not going to try and block it.

I will be making sure that the files in PC\VS9.0 do still work
properly; I could also try to adjust paths in Tools\msi such that you
would only need to use PC\VS9.0 instead of PCbuild.  I have yet to
successfully build an MSI for any Python release, though, so I can't
make any promises about that working.

> I don't see any real need to emit scary warnings about compiler compatibility - a simple warning like in 3.5 for old compilers is fine.

That's the one I was talking about, actually :).  Describing it as a
"big scary" warning was probably a bit much.

>> Using the backported project files to build 2.7 would require two versions of
>> Visual Studio to be installed; VS2010 (or newer) would be required in addition
>> to VS2008. All Windows core developers should already have VS2010 for Python 3.4
>> (and/or VS2015 for 3.5) and I expect that anyone else who cares enough to still
>> have VS2008 probably has (or can easily get) one of the free editions of VS 2010
>> or newer, so I don't consider this to be a major issue.
>
> It may have a workaround, but it also could be a serious blocking issue for those who can't install another version. Especially since there's no benefit to the resulting builds.

The easiest workaround would be to use the project files in PC\VS9.0.
It might work to install only whatever gets you a new-enough MSBuild,
but I haven't tested that at all and thus don't know.  I will tell you
that it works to build the backported pcbuild.proj with
\Windows\Microsoft.NET\Framework\v4.0.30319\MSBuild.exe, invoked from
a clean environment on a machine with VS 2008, 2010, 2013, and 2015RC
installed, though.

>> The backported files could be added alongside the old files in PCbuild, in a
>> better-named 'NewPCbuild' directory, or in a subdirectory of PC. I would rather
>> replace the old project files in PCbuild, though; I'd like for the backported
>> files to be the recommended way to build, complete with support from
>> PCbuild/build.bat which would make the new project files the default for the
>> buildbots.
>
> Agreed, just replace them. PCBuild is messy enough with the output files in there (I'd avoid moving them - plenty of the stdlib and test suite expects them to be there), we don't need duplicate project files.

That probably explains a few of the failures I'm still seeing that I
hadn't dug into yet.

-- 
Zach