$ git clone -n https://src.fedoraproject.org/rpms/diffoscope.git /var/lib/mock/f40-build-2493497-61664/root/chroot_tmpdir/scmroot/diffoscope
Cloning into '/var/lib/mock/f40-build-2493497-61664/root/chroot_tmpdir/scmroot/diffoscope'...
$ git fetch origin 44fa29cc5856347e58161ed96fb297c2ae4de667:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/diffoscope
 * [new ref]         44fa29cc5856347e58161ed96fb297c2ae4de667 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 44fa29c Rebuilt for java-21-openjdk as system jdk