Buildfarm broken for 9.3 and up

My push to branches 9.3 and up seems to have broken the buildfarm 
with this:

error: object file /home/pgfarm/buildroot/pgmirror.git/objects/93/d7706cbf2ce58e63ab8bbc9d16453b2c792ed4 is empty
error: unable to find 93d7706cbf2ce58e63ab8bbc9d16453b2c792ed4
fatal: SHA1 COLLISION FOUND WITH 93d7706cbf2ce58e63ab8bbc9d16453b2c792ed4 !
fatal: index-pack failed
Your configuration specifies to merge with the ref 'master'
from the remote, but no such ref was fetched.

I don't see any problems on my machine, although when I attempt to 
checkout the referenced SHA1 value on branch REL9_3_STABLE, I get 
this:

kgrittn@Kevin-Desktop:~/pg/REL9_3_STABLE$ git checkout 93d7706cbf2ce58e63ab8bbc9d16453b2c792ed4
fatal: reference is not a tree: 93d7706cbf2ce58e63ab8bbc9d16453b2c792ed4

I can't find that SHA1 in my git log.

I have no clue what to do about this.

-- 
Kevin Grittner
EDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company