$ git clone -n https://src.fedoraproject.org/rpms/jcuber.git /var/lib/mock/f40-build-694855-12764/root/chroot_tmpdir/scmroot/jcuber
Cloning into '/var/lib/mock/f40-build-694855-12764/root/chroot_tmpdir/scmroot/jcuber'...
$ git fetch origin d89d8a9ddafa782796a733aea9ea7feb8512ecae:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/jcuber
 * [new ref]         d89d8a9ddafa782796a733aea9ea7feb8512ecae -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at d89d8a9 Rebuilt for java-21-openjdk as system jdk