$ git clone -n https://src.fedoraproject.org/rpms/gstreamer1-plugin-openh264.git /var/lib/mock/f40-build-2615810-64249/root/chroot_tmpdir/scmroot/gstreamer1-plugin-openh264
Cloning into '/var/lib/mock/f40-build-2615810-64249/root/chroot_tmpdir/scmroot/gstreamer1-plugin-openh264'...
$ git fetch origin 64481882fd18ce790ea8bcccb3c61b09e004fdf7:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/gstreamer1-plugin-openh264
 * [new ref]         64481882fd18ce790ea8bcccb3c61b09e004fdf7 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 6448188 Added the README