$ git clone -n https://src.fedoraproject.org/rpms/rust-derivative.git /var/lib/mock/f40-build-2248336-53948/root/chroot_tmpdir/scmroot/rust-derivative
Cloning into '/var/lib/mock/f40-build-2248336-53948/root/chroot_tmpdir/scmroot/rust-derivative'...
$ git fetch origin eb8b9d60eef9bcd3d10444c18f4c7875dbf5fb99:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-derivative
 * [new ref]         eb8b9d60eef9bcd3d10444c18f4c7875dbf5fb99 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at eb8b9d6 Rebuilt for https://fedoraproject.org/wiki/Fedora_39_Mass_Rebuild