https://notabug.org/anomie/chihaya is linked to as a repo on https://notabug.org/anomie/'s page but it goes to an internal error
I don't have access to the logs so I can't really say what the problem is... but maybe you can try deleting and re-creating the repository? In the past, I remember 500 errors associated with bad .git folders.
I am not anomie, so I can't delete it.
Since a few days my repo (https://notabug.org/themightyglider/RogueBoxAdventures) gives me an 500 error as well.
It is a mirror of: https://git.tuxfamily.org/rba/rogueboxadventures.git