Support for setuptools extras

[coderanger@…]

Attached is a patch for supporting setuptools extras, both for load ordering, and for optional entry points. When using the optional entry points, you need setuptools 0.6b1 or higher, due to a bug in the entry point parser in earlier versions. If you are not using any plugins that require this (which can mark themselves as depending on the needed versions of setuptools), then it should work with any of 0.6alpha versions. The patch is against r3356 of trunk.

[coderanger@…]

Patch for extras support

[coderanger@…]

Files in the correct order this time

[Christian Boos]

Probably a better fit for this ticket would be 0.11 (or 0.10.1?), along with the source:sandbox/setuptools branch integration.

[coderanger]

This isn't much more dependent on setuptools than the current system.

[Christopher Lenz]

Can you elaborate on why this is actually required? We're using extras in the SpamFilter plugin, and that has been working okay AFAICT.

[coderanger]

Currently extras will not be considered when doing the dependency ordering. Using a simpler solution has the problem that if an extra isn't loadable, it will cause the entire plugin to not load.

[Christopher Lenz]

Hmm, the SpamFilter plugin works when e.g. dnsresolver isn't installed, only the tracspamfilter.filters.dnsblacklist module isn't loaded. I'm still not sure I really understand the problem :-P

[coderanger]

If you had another plugin with an optional depenency on something like WebAdmin, if you list "admin" as an depending on TracWebAdmin, the current code will not try to make sure the TracWebAdmin distribution is loaded before that plugin. If you list the dep in install_requires, the loader will try to do the right thing when it can. For something like dnspython, which is installed centrally, this isn't a problem, but if WebAdmin is installed as a local egg, it needs to be loaded before anything can import from it. This patch examines all extras, and trys to make sure they are loaded in order.

[coderanger]

Its worth noting that using extras at all requires setuptools 0.6b2 (or maybe 0.6b1, I forget), and given the slugish pace that most distros have with respect to getting new setuptools packages available, targetting this for 0.11 is probably about right.

[Noah Kantrowitz <coderanger@…>]

Updated version against r4667

[Noah Kantrowitz <coderanger@…>]

I just posted a new version, are there any objections to this still?

[Matthew Good]

Replying to Noah Kantrowitz <coderanger@yahoo.com>:

I just posted a new version, are there any objections to this still?

No, we should definitely support this.

[Christian Boos]

Noah, you should really read TracDev/CodingStyle once, in particular about our obsessive adherence to the 80-characters wide lines rule ;)

[Matthew Good]

This has been fixed with r4832 which uses new pkg_resources APIs which take extras into account when loading Trac entry points.