PSTricks broken in Plain TeX?

Question

% Plain LuaTeX or Plain XeTeX
\input luaotfload.sty% comment this out for XeTeX
\input pst-circ

\pspicture(-1, 0)(3.5, 4.5)
\circledipole[labeloffset = 0](0, 3)(3, 3){V}
\coil[dipolestyle=curved](0, 1)(3, 1){}
\wire(0, 1)(0, 3)
\wire(3, 1)(3, 3)
\endpspicture

This produces an error message in both (XeTeX and LuaTeX):

Undefined control sequence.
\RequirePackage

When I run this example with LuaTeX and without \input luaotfload.sty then there are even more errors and no picture is produced.

What is wrong here? According to the manual of PSTricks it should work with Plain TeX.

Answer 1

This is a bug in pstricks.tex which you should report.

It tests for LaTeX

\expandafter\ifx\csname @latexerr\endcsname\relax % do we have TeX? then @latexerr isn't defined
  \input pstricks-tex.def
\fi

but \csname defines \@latexerr to be \relax so a later test in the same file

  \ifdefined\@latexerr % format is latex
    \RequirePackage{pgffor} % pgffor depends on pgfkeys

takes the wrong branch