$ git clone -n https://src.fedoraproject.org/rpms/rust-local-channel.git /var/lib/mock/f40-build-2714182-72261/root/chroot_tmpdir/scmroot/rust-local-channel
Cloning into '/var/lib/mock/f40-build-2714182-72261/root/chroot_tmpdir/scmroot/rust-local-channel'...
$ git fetch origin b21a17eb3740961a6a8069c8440538e68864ec21:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-local-channel
 * [new ref]         b21a17eb3740961a6a8069c8440538e68864ec21 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at b21a17e Rebuilt for https://fedoraproject.org/wiki/Fedora_40_Mass_Rebuild