$ git clone -n https://src.fedoraproject.org/rpms/mpv.git /var/lib/mock/f40-build-2265058-54583/root/chroot_tmpdir/scmroot/mpv
Cloning into '/var/lib/mock/f40-build-2265058-54583/root/chroot_tmpdir/scmroot/mpv'...
$ git fetch origin 628c52537e084f3a3cff6107edac9c7e2e7cccf4:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/mpv
 * [new ref]         628c52537e084f3a3cff6107edac9c7e2e7cccf4 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 628c525 Update to 0.37.0