$ git clone -n https://src.fedoraproject.org/rpms/btbuilder.git /var/lib/mock/f40-build-2274818-55031/root/chroot_tmpdir/scmroot/btbuilder
Cloning into '/var/lib/mock/f40-build-2274818-55031/root/chroot_tmpdir/scmroot/btbuilder'...
$ git fetch origin 6d1c037f66ba8c7bb2d5ca40522b7090f784de12:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/btbuilder
 * [new ref]         6d1c037f66ba8c7bb2d5ca40522b7090f784de12 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 6d1c037 Rebuilt for https://fedoraproject.org/wiki/Fedora_40_Mass_Rebuild