$ git clone -n https://src.fedoraproject.org/rpms/btbuilder.git /var/lib/mock/f40-build-780360-130935/root/chroot_tmpdir/scmroot/btbuilder
Cloning into '/var/lib/mock/f40-build-780360-130935/root/chroot_tmpdir/scmroot/btbuilder'...
$ git fetch origin 17eca00caef7b43112f510988b23c23e7ae54ce6:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/btbuilder
 * [new ref]         17eca00caef7b43112f510988b23c23e7ae54ce6 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 17eca00 Rebuilt for https://fedoraproject.org/wiki/Fedora_40_Mass_Rebuild