Running social4git sync occasionally (!) produces an error:

malformed unpack status: 0024unpack index-pack abnormal exit

This is flaky behavior. Rerunning sync a few times tends to fix the problem.
The error comes from the github servers.

It is currently unclear whether this issue is due to:

• a bug in go-git (the git client library we use)
• a non-standard corner-case behavior on the github git servers