$ git clone -n https://src.fedoraproject.org/rpms/gstreamer1-plugins-base.git /var/lib/mock/f41-build-808243-145747/root/chroot_tmpdir/scmroot/gstreamer1-plugins-base
Cloning into '/var/lib/mock/f41-build-808243-145747/root/chroot_tmpdir/scmroot/gstreamer1-plugins-base'...
$ git fetch origin c79678a21bd8836996f07f64bc5e5395684f487c:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/gstreamer1-plugins-base
 * [new ref]         c79678a21bd8836996f07f64bc5e5395684f487c -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at c79678a Disable libvisual in RHEL builds