$ git clone -n https://src.fedoraproject.org/rpms/jgit.git /var/lib/mock/f40-build-2510185-61706/root/chroot_tmpdir/scmroot/jgit
Cloning into '/var/lib/mock/f40-build-2510185-61706/root/chroot_tmpdir/scmroot/jgit'...
$ git fetch origin a6df3d08d915ef8b01553a40e32a896f64bcf30c:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/jgit
 * [new ref]         a6df3d08d915ef8b01553a40e32a896f64bcf30c -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at a6df3d0 Rebuilt for java-21-openjdk as system jdk