$ git clone -n https://src.fedoraproject.org/rpms/golang-x-sync.git /var/lib/mock/f38-build-side-42-init-devel-589814-26120/root/chroot_tmpdir/scmroot/golang-x-sync
Cloning into '/var/lib/mock/f38-build-side-42-init-devel-589814-26120/root/chroot_tmpdir/scmroot/golang-x-sync'...
$ git fetch origin ba089bcc60250b9de3141693bb22122436c972cd:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/golang-x-sync
 * [new ref]         ba089bcc60250b9de3141693bb22122436c972cd -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at ba089bc Update to latest version