$ git clone -n https://src.fedoraproject.org/rpms/CImg.git /var/lib/mock/f38-build-side-42-init-devel-603413-26218/root/chroot_tmpdir/scmroot/CImg
Cloning into '/var/lib/mock/f38-build-side-42-init-devel-603413-26218/root/chroot_tmpdir/scmroot/CImg'...
$ git fetch origin aa08672a57b5591711d1bc947d3be28aaf8feae5:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/CImg
 * [new ref]         aa08672a57b5591711d1bc947d3be28aaf8feae5 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at aa08672 Rebuilt for https://fedoraproject.org/wiki/Fedora_38_Mass_Rebuild