$ git clone -n https://src.fedoraproject.org/rpms/gstreamer1-plugin-libav.git /var/lib/mock/f41-build-861168-169427/root/chroot_tmpdir/scmroot/gstreamer1-plugin-libav
Cloning into '/var/lib/mock/f41-build-861168-169427/root/chroot_tmpdir/scmroot/gstreamer1-plugin-libav'...
$ git fetch origin 0c1afb3443c37d22a047c0b95b3c63cf707433d1:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/gstreamer1-plugin-libav
 * [new ref]         0c1afb3443c37d22a047c0b95b3c63cf707433d1 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 0c1afb3 1.24.9