$ git clone -n https://src.fedoraproject.org/rpms/golang-go4.git /var/lib/mock/f39-build-1788764-41732/root/chroot_tmpdir/scmroot/golang-go4
Cloning into '/var/lib/mock/f39-build-1788764-41732/root/chroot_tmpdir/scmroot/golang-go4'...
$ git fetch origin c8c68ca116105af293b4c50ed2a5b0b467bdef52:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/golang-go4
 * [new ref]         c8c68ca116105af293b4c50ed2a5b0b467bdef52 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at c8c68ca Bump to commit 214862532bf518db360e7ecc2b8a94b66a10c176