/usr/bin/bzr incorrectly uses /usr/bin/env python
I just upgraded feisty with bzr 0.90~rc1-1 through update-manager. Then I tried to do a "bzr --version" and this complained about not being able to find bzrlib.
The problem is that /usr/bin/bzr incorrectly invokes python on its #! line.
It uses "#!/usr/bin/env python" which is the appropriate line to use for source installations but it is not the right line to use for system installations. A system tool requires the system python, not the first python on your $PATH. This breaks for everybody who develops Python or has another python on their $PATH.
No system tool ever should use "#!/usr/bin/env python" and in fact setuptools/
Note that you want your packager to do the right thing here. Just tweaking that line in the source code repository isn't right either because then it will be broken for bzr developers using and testing different python's than the system one.