$ git clone -n https://src.fedoraproject.org/rpms/golang-gopkg-natefinch-lumberjack-2.git /var/lib/mock/f41-build-1036596-18741/root/chroot_tmpdir/scmroot/golang-gopkg-natefinch-lumberjack-2
Cloning into '/var/lib/mock/f41-build-1036596-18741/root/chroot_tmpdir/scmroot/golang-gopkg-natefinch-lumberjack-2'...
$ git fetch origin 2cfeddaf083ce73013998d663be33bfe554fc764:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/golang-gopkg-natefinch-lumberjack-2
 * [new ref]         2cfeddaf083ce73013998d663be33bfe554fc764 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 2cfedda Fix FTBFS