$ git clone -n https://src.fedoraproject.org/rpms/gstreamer1-plugin-libav.git /var/lib/mock/f41-build-836851-158931/root/chroot_tmpdir/scmroot/gstreamer1-plugin-libav
Cloning into '/var/lib/mock/f41-build-836851-158931/root/chroot_tmpdir/scmroot/gstreamer1-plugin-libav'...
$ git fetch origin 7b6a64a1b0e4def48aab73cc67ba2aa1961818fa:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/gstreamer1-plugin-libav
 * [new ref]         7b6a64a1b0e4def48aab73cc67ba2aa1961818fa -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 7b6a64a 1.24.6