$ git clone -n https://src.fedoraproject.org/rpms/lilypond.git /var/lib/mock/f40-build-1507169-23890/root/chroot_tmpdir/scmroot/lilypond
Cloning into '/var/lib/mock/f40-build-1507169-23890/root/chroot_tmpdir/scmroot/lilypond'...
$ git fetch origin 187330692599f839f0af0cee7ef0619bf8211a4a:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/lilypond
 * [new ref]         187330692599f839f0af0cee7ef0619bf8211a4a -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 1873306 Update guile version