Bugzilla Bug 216835

Emerge of avahi with the "python" use flag produces an 'avahi' package in the
python site-packages directory, but it is lacking critical files which are
required for it to function.

This is an upstream problem as their python support is very sketchy. Problem
remains in their current head at the time of this writing.

Bug is being reported so that other Gentoo users will be able to use avahi from
python if they do not also happen to have the gtk use flag enabled.

Reproducible: Always

Steps to Reproduce:
1. Emerge avahi with dbus and python use flags, but not the gtk use flag
2. Attempt to use the avahi python module


Actual Results:  
Execution of Python program will fail reporting that there is no avahi module


Expected Results:  
Avahi should be accessible from python using dbus if only the python and dbus
use flags are enabled.



Suggest Avahi ebuild emit warning that python support is non-functional if
python use flag is enabled but either of the dbus or gtk use flags are missing.

Cause of the problem can be seen here:
http://avahi.org/browser/trunk/avahi-python/avahi/Makefile.am?rev=1540
around lines 55-58

The ebuild now checks for these flags.