$ git clone -n https://src.fedoraproject.org/rpms/fbrnch.git /var/lib/mock/f43-build-60920353-6585857/root/chroot_tmpdir/scmroot/fbrnch
Cloning into '/var/lib/mock/f43-build-60920353-6585857/root/chroot_tmpdir/scmroot/fbrnch'...
$ git fetch origin 51ca1bc0a7719f7bf04cb9d4753325781b5f2a0f:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/fbrnch
 * [new ref]         51ca1bc0a7719f7bf04cb9d4753325781b5f2a0f -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 51ca1bc Update to 1.7.1