Hi David,
Sorry for the delayed reply.
makeinfo -D "somedir somevalue"
That is the intended syntax (same as ever). It works for me, for
instance with the minimal file
\input texinfo
@setfilename includevalue.info
@verbatiminclude @value{somedir}/somefile.txi
@bye
And then running with
makeinfo -D "somedir ." includevalue.tex
where somefile.txi is another trivial file in the current directory.
Can you show your actual document that fails (cut down if possible),
with the actual directory and file names? And error messages given by
makeinfo, if any. Perhaps some kind of (mis)interpretation is
happening.
Best,
Karl
