Command failed: GIT backend not available

[Marco Menzel]

Binary package hint: trac-git

Hello, there seems to be some problems with trac-git on
Ubuntu 10.10

Trac
New: yes
State: installed
Automatically installed: no
Version: 0.11.7-4

Package: trac-git
New: yes
State: installed
Automatically installed: no
Version: 0.0.20100513-2ubuntu1

Package: git
New: yes
State: installed
Automatically installed: no
Version: 1:1.7.1-1.1

trac-git doesn't work

trac.log:

Trac[git_fs] ERROR: GitError: Could not retrieve GIT version

trac-admin and resync:

Resyncing repository history...
/usr/lib/python2.6/dist-packages/tracext/git/git_fs.py:70: DeprecationWarning: BaseException.message has been deprecated as of Python 2.6
  self.log.error("GitError: "+e.message)
Command failed: GIT backend not available

Any Ideas?