[Python-Dev] PEP 405 (Python Virtual Environments) and Windows script support

[Nick Coghlan]

On Tue, May 29, 2012 at 5:37 AM, Vinay Sajip <vinay_sajip at yahoo.co.uk> wrote:
> Antoine Pitrou <solipsis <at> pitrou.net> writes:
>
>> Regardless of what the executable is or does, its source code must be
>> included somewhere in the Python source tree (and, preferably, there
>> should be a simple procedure to build the binaries).
>
> I understand that. Does it need to be checked in right now? It will need
> integrating with the existing VS2010 solution file, and at the moment I cannot
> do that integration because I haven't yet got a full VS2010 build environment,
> just a VS2008 one.

It would have been better if the issue of script management on Windows
had been raised in PEP 405 itself - I likely would have declared PEP
397 a dependency *before* accepting it (even if that meant the feature
missed the alpha 4 deadline and first appeared in beta 1, or
potentially even missed 3.3 altogether).

However, I'm not going to withdraw the acceptance of the PEP over this
- while I would have made a different decision at the time given the
additional information (due to the general preference to treat Windows
as a first class deployment target), I think reversing my decision now
would make the situation worse rather than better.

That means the important question is what needs to happen before beta
1 at the end of June. As I see it, we have two ways forward:

1. My preferred option: bring PEP 397 up to scratch as a specification
for the behaviour of the Python launcher (perhaps with Vinay stepping
up as a co-author to help Mark if need be), find a BDFL delegate (MvL?
Brian Curtin?) and submit that PEP for acceptance within the next few
weeks. The updated PEP 397 should include an explanation of exactly
how it will help with the correct implementation of PEP 405 on Windows
(this may involve making the launcher pyvenv aware).

2. The fallback option: remove the currently checked in build
artifacts from source control and incorporate them into the normal
Windows build processes (both the main VS 2010 process, and at least
the now-legacy VS 2008 process)

For alpha 4, I suggest going with MvL's suggestion - drop the binaries
from Mercurial and accept that this aspect of PEP 405 simply won't
work on Windows until the first beta.

Regards,
Nick.

-- 
Nick Coghlan   |   ncoghlan at gmail.com   |   Brisbane, Australia