$ git clone -n https://src.fedoraproject.org/rpms/golang-gocloud.git /var/lib/mock/f41-build-1311801-23509/root/chroot_tmpdir/scmroot/golang-gocloud
Cloning into '/var/lib/mock/f41-build-1311801-23509/root/chroot_tmpdir/scmroot/golang-gocloud'...
$ git fetch origin 65fbcce344d08622d2fd70869566ebbdc397be4a:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/golang-gocloud
 * [new ref]         65fbcce344d08622d2fd70869566ebbdc397be4a -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 65fbcce Fix FTBFS