Git suddenly started to choke on “git pull” for only one repo

Question

Yesterday, at some point in time, my Git for Windows suddenly started to choke (hang forever) on git pull for only one repo. I managed to pull changes ten times this day, I started to fail on eleventh pull.

Since the same happend to TortoiseGit, and after doing some research, I narrowed the problem to TortoisePlink (used by Git for Windows) never exiting (both Git for Windows and TortoiseGit unhanged and continued normally, when I killed TortoisePlink using Task Manager).

I have updated services (including Putty) to newest version, applied solution and problem is now solved.

I understand, where problem originates and how to solve it. However, there are certain things, that I don't understand or even see them as weird, so I'd appreciate, if someone could shed some light on this case.

Accordind to solution, problem is caused by some misunderstanding between SSH client and my Gerrit server. If that is true, then how it is possible that:

1. Problem occurs only for git pull. The git push and other remote-related, authentication-requiring commands works normally.

2. Problem started to occur suddenly. Yesterday, until 14:25 UTC, I was able to push/pull changes for this repo. I did around 10 pulls. And suddenly, without any change in my configuration, updating any software and actually doing anything else, my git started to choke on git pull (there were also no changes to server / Gerrit). And I wasn't able to pull anything until applying mentioned solution.

3. Problem occured to one repo only. Yes, one repo. I have another repo (another project) on the very same Gerrit server and I was able to pull / push everything without any problems, yesterday before / after choke on antoher repo and today before / after applying the solution.

If there are some changes / bugs in SSH layer (in general), then I really can't understand, how can they influent only: (a) one way (pull, push works), (b) one repo (other works) and (c) happen suddenly (all was working minutes before). Can someone enlighten me on this?