Got 500 error after small commit & push

I have a private repository (I made it public for now), and after not so big and strange my friend's commit I cannot even pull the changes, as well as watch them in browser.

Repo address:
https://bitbucket.org/alucard_desu/test-repository

Commit:
https://bitbucket.org/alucard_desu/test-repository/commits/f89abb6d506a3c5ec4a7dc847c1f2b2a61f74f8e

Copy-paste from "This might be useful in debugging the problem" field:
c9e8ef0ef9524777a8e79f5bccefa43e

I am sure that is an important issue in your core functionality, so, please, pay attention.