$ git clone -n https://src.fedoraproject.org/rpms/rust-tower-layer.git /var/lib/mock/f40-build-2658294-66917/root/chroot_tmpdir/scmroot/rust-tower-layer
Cloning into '/var/lib/mock/f40-build-2658294-66917/root/chroot_tmpdir/scmroot/rust-tower-layer'...
$ git fetch origin cad77f9079c9484bd7f968b74cc267ca1ff1b12a:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-tower-layer
 * [new ref]         cad77f9079c9484bd7f968b74cc267ca1ff1b12a -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at cad77f9 Rebuilt for https://fedoraproject.org/wiki/Fedora_40_Mass_Rebuild