[merge] look for plugins in arch-independent site directory (was Re: Bundling more plugins into bzrtools)

[John Arbash Meinel]

John Arbash Meinel has voted comment.
Status is now: Semi-approved
Comment:
So... I believe the original problem was that bzrlib was being installed 
to a CPU specific location (/usr/lib64/python/site-packages/bzrlib), 
while the plugins should have been arch independent (which I guess is 
/usr/lib/python/site-packages/*)

I can't say that I know how fedora solved these issues. But if it has 
the python standard library in /usr/lib/python/* how does it know to 
import from /usr/lib64/python/*?

With whatever mechanism that was, could we not just import 
"bzrlib._compiled_foo" from there, and leave all the rest of the .py 
files in /usr/lib/python/* ?

I also don't know if 'python-central' solves any of this. It seems to be 
focusing more on keeping track of things based on python version. (So 
with 2.4 and 2.5 installed, /usr/lib/python2.4/site-packages/bzrlib/*.py 
are symlinks to the version-agnostic place, which _foo.so and *.pyc are 
kept locally.)

Anyway, there are some other effects of this patch that we didn't 
discuss. Namely that running from source: "~/dev/bzr/bzr.dev/bzr foo" 
will load the plugins installed in 
/usr/lib/python/site-packages/bzrlib/plugins/*

I think Robert's argument was that, yes, we *should* have a system-wide 
install location (possibly set up in /etc/bazaar.conf), but it should 
probably be independent from where bzrlib itself is installed.

I don't feel like I've thought through the implications enough to give a 
final vote on this. It feels a little like a workaround for a workaround 
that another system chose to use.

For details, see: 
http://bundlebuggy.aaronbentley.com/request/%3C47CACCAA.3060700%40ukr.net%3E