$ git clone -n https://src.fedoraproject.org/rpms/golang-x-perf.git /var/lib/mock/f45-build-12809-443/root/chroot_tmpdir/scmroot/golang-x-perf
Cloning into '/var/lib/mock/f45-build-12809-443/root/chroot_tmpdir/scmroot/golang-x-perf'...
$ git fetch origin 2c9e652afb096ffb6a65dcaab9d659059c7d1786:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/golang-x-perf
 * [new ref]         2c9e652afb096ffb6a65dcaab9d659059c7d1786 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 2c9e652 Update to 19be9d8