[Distutils] Handling the binary dependency management problem

[Paul Moore]

On 2 December 2013 22:26, Nick Coghlan <ncoghlan at gmail.com> wrote:
>>Whether solving the Unix
>> issues is worth it is the Unix users' call - I'll help solve the
>> issues, if they choose to, but I won't support abandoning the existing
>> Windows solution just because it can't be extended to cater for Unix
>> as well.
>
> You appear to still be misunderstanding my proposal, as we're actually in
> violent agreement. All that extra complexity you're worrying about is
> precisely what I'm saying we should *leave out* of the wheel spec. In most
> cases of accelerator and wrapper modules, the static linking and/or bundling
> solutions will work fine, and that's the domain I believe we should
> *deliberately* restrict wheels to, so we don't get distracted trying to
> solve an incredibly hard external dependency management problem that we
> don't actually need to solve at the wheel level, since anyone that actually
> needs it solved can just bootstrap conda instead.

OK. I think I've finally seen what you're suggesting, and yes, it's
essentially the same as I'd like to see (at least for now). I'd hoped
that wheels could be more useful for Unix users than seems likely now
- mainly because I really do think that a lot of the benefits of
binary distributions are *not* restricted to Windows, and if Unix
users could use them, it'd lessen the tendency to think that
supporting anything other than source installs was purely "to cater
for Windows users not having a compiler" :-) But if that's not a
practical possibility (and I defer to the Unix users' opinions on that
matter) then so be it.

On the other hand, I still don't see where the emphasis on conda in
your original message came from. There are lots of "full stack"
solutions available - I'd have thought system packages like RPM and
apt are the obvious first suggestion for users that need a curated
stack. If they are not appropriate, then there are Enthought,
ActiveState and Anaconda/conda that I know of. Why single out conda to
be blessed?

Also, I'd like the proposal to explicitly point out that 99% of the
time, Windows is the simple case (because static linking and bundling
DLLs is common). Getting Windows users to switch to wheels will be
enough change to ask, without confusing the message. A key point here
is that packages like lxml, matplotlib, or Pillow would have
"arbitrary binary dependency issues" on Unix, but (because of static
linking/bundling) be entirely appropriate for wheels on Windows. Let's
make sure the developers don't miss this point!

Paul