my $nr = grep(/\A[0-9]+\z/, readdir($dh)) or
return warn("$xpfx has no shards\n"); # true
return reopen($self) if $nr == ($self->{nshard} // -1);
my $nr = grep(/\A[0-9]+\z/, readdir($dh)) or
return warn("$xpfx has no shards\n"); # true
return reopen($self) if $nr == ($self->{nshard} // -1);