$ git clone -n https://src.fedoraproject.org/rpms/rhythmbox-alternative-toolbar.git /var/lib/mock/f39-build-1781699-41557/root/chroot_tmpdir/scmroot/rhythmbox-alternative-toolbar
Cloning into '/var/lib/mock/f39-build-1781699-41557/root/chroot_tmpdir/scmroot/rhythmbox-alternative-toolbar'...
$ git fetch origin ae36a59567b8a173d4bafd8be26fa2a08870964b:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rhythmbox-alternative-toolbar
 * [new ref]         ae36a59567b8a173d4bafd8be26fa2a08870964b -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at ae36a59 Update to 0.20.4