$ git clone -n https://src.fedoraproject.org/rpms/seamonkey.git /var/lib/mock/f39-build-1983157-43346/root/chroot_tmpdir/scmroot/seamonkey
Cloning into '/var/lib/mock/f39-build-1983157-43346/root/chroot_tmpdir/scmroot/seamonkey'...
$ git fetch origin 52f8016ecfa3f6594846290482b6f12e858070ac:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/seamonkey
 * [new ref]         52f8016ecfa3f6594846290482b6f12e858070ac -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 52f8016 .