$ git clone -n https://src.fedoraproject.org/rpms/julia.git /var/lib/mock/f40-build-770592-125863/root/chroot_tmpdir/scmroot/julia
Cloning into '/var/lib/mock/f40-build-770592-125863/root/chroot_tmpdir/scmroot/julia'...
$ git fetch origin b584d5609fab3a981c4a95d6b1ffa21514c4288b:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/julia
 * [new ref]         b584d5609fab3a981c4a95d6b1ffa21514c4288b -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at b584d56 Rebuild for libgit2 1.7.x