implement access control which is finer grained than the one
based on filesystem group.
+The standard output of this hook is sent to /dev/null; if you
+want to report something to the git-send-pack on the other end,
+you can redirect your output to your stderr.
+
post-update
-----------
The default post-update hook, when enabled, runs
`git-update-server-info` to keep the information used by dumb
transport up-to-date.
+
+The standard output of this hook is sent to /dev/null; if you
+want to report something to the git-send-pack on the other end,
+you can redirect your output to your stderr.