Collecting changes from VCS fails with "VcsException: 'git fetch' command failed... Short read of block"

Symptoms

Collecting changes for the repository fails with the following error message:

Error:
Caused by: jetbrains.buildServer.vcs.VcsException: 
'git fetch' command failed (repository dir: <TeamCity Data Directory>/system/caches/git/git-<hash>.git). 
stderr: Short read of block.

Cause

The repository directory in the error message indicates the possibility of the corrupted TeamCity git cache, possibly due to a disk space issue.

Resolution

1. Ensure there is sufficient amount of free disk space on the volume where <TeamCity Data Directory>/system/caches is situated.
2. Reset the git cache:
   • Option A: using the Reset link on the Administration > Diagnostics > Caches > git page.
   • Option B: manually remove only the <TeamCity Data Directory>/system/caches/git/git-<hash>.git directory specified in the error message.

Note: resetting Git cache may increase the duration of the next change collection for the affected repositories.