$ git clone -n https://src.fedoraproject.org/rpms/gstreamer1-plugins-bad-free.git /var/lib/mock/f41-build-836891-158940/root/chroot_tmpdir/scmroot/gstreamer1-plugins-bad-free
Cloning into '/var/lib/mock/f41-build-836891-158940/root/chroot_tmpdir/scmroot/gstreamer1-plugins-bad-free'...
$ git fetch origin fd33bbaa5eadde5d22b737180eeac6eac8b9f186:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/gstreamer1-plugins-bad-free
 * [new ref]         fd33bbaa5eadde5d22b737180eeac6eac8b9f186 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at fd33bba sources