I just recently submitted an update of my package to CRAN, and I was notified that a line in an .Rd file was too wide. Using the latest Rpatched version, I ran the R CMD check, everything checked out ok. I ran the --as-cran on the tarball and everything is ok. When I examined the .PDF file created after R CMD build, I do see that the line in the .PDF help file extended beyond page margin.
My question is where and how do I check for errors in the creation of the .PDF file? I've checked through Writing R Extensions, etc. and I can't find a specific statement.
Build and check your package R CMD build mypkg && R CMD check mypkg_1.2.3.tar.gz. Then look in mypkg.Rcheck/Rdlatex.log for warnings (like Overful \hbox) while processing the Rd file to latex.