gnuplot-4.2 supports wxwidgets frontend optionally. This can be conntrolled by
wxwindows use flag. But it takes no effect actually because configure gets
--with/without-wxwidgets option instead of exptected
--enable/disable-wxwindows. After that configure fallbacks into autodetection.
(Accidentally, I have installed only wxGTK and USE=-wxwindows emerge gnuplot
detects wx-config but crashes inside make on missing something.)
Replacing use_with with use_enable on wxwindows condition in ebuild solves the
problem for me.
Reproducible: Always