Depend on a new enough setuptools to preserve data file access modes.

debian/control.in

@@ -3,7 +3,7 @@ Section: admin
 Priority: optional
 Maintainer: Tommi Virtanen <tv@debian.org>
 Standards-Version: 3.7.2
-Build-Depends: @cdbs@
+Build-Depends: @cdbs@, python-setuptools (>= 0.6c5)
 
 Package: gitosis
 Section: admin

setup.py

@@ -56,5 +56,12 @@ arbitrary commands.
 
     # templates need to be a real directory, for git init
     zip_safe=False,
+
+    install_requires=[
+        # setuptools 0.6a9 will have a non-executeable post-update
+        # hook, this will make gitosis-admin settings not update
+        # (fixed in 0.6c5, maybe earlier)
+        'setuptools>=0.6c5',
+        ],
     )