$ git clone -n https://src.fedoraproject.org/rpms/schismtracker.git /var/lib/mock/f42-build-side-1-3500227-45966/root/chroot_tmpdir/scmroot/schismtracker
Cloning into '/var/lib/mock/f42-build-side-1-3500227-45966/root/chroot_tmpdir/scmroot/schismtracker'...
$ git fetch origin 6224b0247146b5d5e221393324f574d94b07e0f4:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/schismtracker
 * [new ref]         6224b0247146b5d5e221393324f574d94b07e0f4 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 6224b02 bump version2