$ git clone -n https://src.fedoraproject.org/rpms/bst-external.git /var/lib/mock/f40-build-2686011-68045/root/chroot_tmpdir/scmroot/bst-external
Cloning into '/var/lib/mock/f40-build-2686011-68045/root/chroot_tmpdir/scmroot/bst-external'...
$ git fetch origin 135ca92ca56d070d70f7feaf26742d4890fab953:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/bst-external
 * [new ref]         135ca92ca56d070d70f7feaf26742d4890fab953 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 135ca92 Rebuilt for https://fedoraproject.org/wiki/Fedora_40_Mass_Rebuild