[Matplotlib-users] Dependencies for Python packages on OS-X

[Christopher B. <Chr...@no...>]

George Nurser wrote:
> Apologies for perhaps raising an old chestnut here.... but these
> issues would not arise if we had separate intel and ppc MacPython
> binaries.

But all sorts of other issues would arise. The tricky bit to all of this 
is getting/building Universal versions of the various dependencies. I 
still have no idea why Apple doesn't just provide a few more common 
libs, like libpng and libfreetype (which is now included with X11, but 
as I understand it, that's an optional install). Anyway as we don't have 
any control over what Apples does (and even less control over what they 
have already not done!), we need other solutions:

My proposal:

We try to build a consensus among the MacPython community about a 
"standard" way to deal with common dependencies. There is now 
more-or-less a consensus that we should provide binaries for MacPython 
(and now 10.5's Apple python) that are statically linked against 
universal versions of all the dependencies. That works great, but the 
truth is that it's a pain in the $$%#@ to get those dependencies built 
right, so we've substantially raised the barrier for folks to build 
binary packages. Also, it seems a bit silly to separately deal with 
something like libpng for multiple packages. I think I've got at least 
four python extensions with libpng.

For example: Fredrik Lundh recently asked on the PIL list for 
recommendations as to what binaries he should provide for OS-X, and for 
someone to build them (he doesn't have a Mac). I set out to do it for 
him, and am still mired in dependency heck. Note that the key 
dependencies are the same as for Matplotlib (libpng, libfreetype)

My proposal for the "standard" way to provide the libs:

Kyng Chaos (William Kyngesburye)'s Frameworks:

http://www.kyngchaos.com/wiki/software:frameworks

He's got UnixImageIO, which provides libpng and others, and freetype, 
plus a bunch of others. They are all build as proper versioned OS-X 
frameworks, as well as a nice little hack where he puts soft links in to 
create a standard "unixy" hierarchy, so that they can be used by libs 
that don't understand frameworks.

Yes, it's a bit extra to tell folks to first install these two 
frameworks, then whatever the python package lib is, but I think it 
really would make it easier all around, particularly for package 
builders, and making things easier for package builders means that more 
binaries would be built properly, which would make things easier for users.

Note: William's Frameworks are all versioned properly, so there would be 
no harm in installing them multiple times, or having multiple versions 
installed. In fact, I think you could build a *.mpkg that had both your 
python package and the frameworks it needs, so that users would have a 
one download and one click install. It wouldn't hurt to have multiple 
packages with the same Frameworks installed this way.

Thoughts?

-Chris


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Chr...@no...