git pull hangs

[Marco Morandini]

> I have killed all those stale connections. Hopefully that will help. (I
> will guess that the working IP for some reason had an open connection.)

First and foremost: this solved it, and now it works. Thank you again!

Now, the embarrassing part: from your logs we found out that the
unique working ip was exiting from a different nat address 131.175.154.246 instead of
131.175.154.248) who didn't reach the maximum number of open sockets. Our fault for not spotting this from our side.
The others (131.175.147.207 and 131.175.147.134) were likely due to me trying to connect from different classrooms in the campus.

We have no idea about why you ended up with those stale connections.
The only clue I have found is

https://stackoverflow.com/questions/6400151/git-daemon-unable-to-allocate-any-listen-sockets-on-host-null-port-9418

: it seems to suggest using --init-timeout=x and --timeout=x with x reasonably small (say 10) launching the git daemon
(don't know if you already have these options in place).
  
At any rate: thank you again for dealing with this.

Marco