like $@, qr/at least two LaTeX::TikZ::Set::Point objects are needed in order to build a polyline/, "creating a $desc from only one Tikz point croaks";
$pl = eval {
like $@, qr/at least two LaTeX::TikZ::Set::Point objects are needed in order to build a polyline/, "creating a $desc from only one Tikz point croaks";
$pl = eval {