+ my $mismatch = [];
+ $req->{xnum} = cur_ibx_xnum($req, $bref, $mismatch) // do {
+ warn "# deleted\n";
+ warn "# mismatch $_->{blob}\n" for @$mismatch;
+ ${$req->{latest_cmt}} = $req->{cur_cmt} //
+ die "BUG: {cur_cmt} unset ($oid)\n";
+ return;
+ };