After hours of debugging with the help of charon and canton7 on the
Freenode #git channel, we found one solution for this:
1. The problem only happens on 1.7.2.5 and possibly earlier. Thus try to
find 1.7.10.4 or newer somewhere.
2. Clone the repository on --bare format with 1.7.10.4:
Some additional information in case this is relevant. It seems the problem
is that the client is not requesting the master ref:
https://gist.github.com/3757035
If you compare the outgoing traffic, you see that this line:
0032want aa293a2f2dd897c8fd8dabbe17417cc42bfdf4f5
Is only present for
