[tex-eplain] eplain and Luatex

[Karl Berry]

    Consider following:

If I \input amstex after \endpackages, luatex runs without error.
Whether it actually does what's needed, I don't know.
It seems the problem is about the color package (not surprisingly, since
that's what loads the output back end). I could cut your example down to:

%error \input amstex
\input eplain
\beginpackages
 \usepackage[dvipsnames]{color}
\endpackages
\input amstex % ok

Lorem ipsum
\bye

The error I get is apparently related to \pagewidth. LuaTeX renamed or
removed many pdftex primitives at one time, and I suspect this is one of
them. I just don't have the time right now, if ever, to delve into it
and figure out the replacement, etc. Sorry. (Unfortunately,
\usepackage{luatex85}, which sometimes works around these rename
problems, didn't help here.)

Best,
Karl

..
(/u/texlive/karl/Master/texmf-dist/tex/latex/graphics/mathcolor.ltx))
! Missing number, treated as zero.
<to be read again> 
\relax 
\pagewidth #1->\hsize #1\relax 
                               \captionwidth@ \hsize \advance \captionwidth at ...

<argument> ...lax \ifdim \paperheight >0pt\relax \pagewidth =
                                                  \paperwidth \pageheight =\...