$ git clone -n https://src.fedoraproject.org/rpms/mediainfo.git /var/lib/mock/f42-build-side-1-3506337-45996/root/chroot_tmpdir/scmroot/mediainfo
Cloning into '/var/lib/mock/f42-build-side-1-3506337-45996/root/chroot_tmpdir/scmroot/mediainfo'...
$ git fetch origin c7627f44fdc522cef0e4b3abd63de11fb5e152a4:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/mediainfo
 * [new ref]         c7627f44fdc522cef0e4b3abd63de11fb5e152a4 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at c7627f4 Fix build arches.