R devel - Jan 2025 - UTF-8 encoding issue with R CMD check with install-args="--latex"

Hi,

this is to report some minor UTF-8 encoding issue with R CMD check with option
--install-args="--latex"
(and possibly more install-args).

More specifically, in my Windows system (see the cloud link below for details on
my system), but also
on the Linux machine of my collaborator Matthias Kohl (CC), the following
command throws errors:

 ????? R CMD check --install-args="--latex"
<pkg>_<version>.tar.gz

I.e., at this command, when checking the pdf version of the manual, pdflatex
throws an error of type

==* checking PDF version of manual ... WARNING
LaTeX errors when creating PDF version.
This typically indicates Rd problems.
LaTeX errors found:
! Undefined control sequence.
l.37 \inputencoding
 ?????????????????? {utf8}
The control sequence at the end of the top line
of your error message was never \def'ed. If you have
==
This is certainly not an urgent issue.

Option --install-args="--latex" can be removed without harm for me, it
somehow survived in my set
of (Windows) batch files I use to build, check, and install my R packages on
Windows, which,
admittedly, makes me a rare species in the R ecosystem.

Still, it would be nice to understand why this happens, so any hints would be
warmly welcome.

Some more details on my testing configuration and my first insights into this
error can be found
here: https://cloudstorage.uni-oldenburg.de/s/kStWp5PNiwJEqfz

Best, Peter Ruckdeschel


	[[alternative HTML version deleted]]

? Thu, 16 Jan 2025 18:09:25 +0100
Peter Ruckdeschel via R-devel <r-devel at r-project.org> ?????:
> this is to report some minor UTF-8 encoding issue with R CMD check
> with option --install-args="--latex" (and possibly more
install-args).
Thank you for a very detailed report!

This doesn't happen on R-4.2.2 or 4.3.1, but it does happen on R-devel.

Comparing the calls from R CMD check to R CMD Rd2pdf, I see no
difference in the environment variables or any significant difference
in the command lines. The command being run ends up being equivalent to

R CMD Rd2pdf <package>.Rcheck/<package>

...and the source of the difference is the presence (or absence) of the
<package>.Rcheck/<package>/latex directory. If I temporarily move it
away during an R CMD check --install-args=--latex run, the command
succeeds.

Indeed, tools:::.pkg2tex says
>> ## First check for a latex dir (from R CMD INSTALL --latex).
>> ## Second guess is this is a >= 2.10.0 package with stored .rds
>> ## files.
>> ## If it does not exist, guess this is a source package.
>> latexdir <- file.path(pkgdir, "latex")
The individual *.tex files in the latex/ subdirectory of the installed
package all do start with an "\inputencoding{utf8}" line.

When the latex/ subdirectory doesn't exist, the !dir.exists(latexdir)
branch is taken, where Rd2latex(...) is called with writeEncoding FALSE, thus
avoiding the problem.

-- 
Best regards,
Ivan