[tlbuild] Custom-built xdvipdfmx cannot find pdftex.map on a basic-scheme TDS

[Karl Berry]

    Is it sensible? Should temxf-var path belong to TEXMFDIST? Or to some
    other env. variable?

In the standard setup, all the trees (including TEXMFDIST and TEXMFVAR,
among others) are defined in the TEXMF variable, as a braced list
{tree1,tree2,...}. Then all the paths start with $TEXMF, and thus look
for files in the same places in all the trees.

I wrote lots of comments in texmf.cnf explaining why it does what it does.

I can't say what's "sensible" or not in what you are doing. If it works
for you and you are happy, then fine :). --best, karl.