Dear CRAN maintainers, R core team, Here are some suggestions to prevent some issues I found in several packages on CRAN. Some of these issues have been reported to their maintainers, but still I believe it would be desirable to enforce these on CRAN or in the corresponding R CMD. - Checks for undeclared sysreqs. There are packages that do not declare some system requirement. E.g., bioacoustics requires fftw and soxr, but no sysreqs are declared; ijtiff links agains jpeg, but it's not declared; there are a handful of packages linking against GSL and not declaring it, such as BayesSAE, BayesVarSel, bnpmr... Speaking of which... it would be *great* to have some standardization in the way sysreqs are declared... But that's another story for another day. - Checks for buildroot path in the installed files. E.g., RUnit calls system.file in man/checkFuncs.Rd, and as a result, the installed manual contains the buildroot path, which should never happen. Another example is TMB, but in this case the buildroot ends up in a binary file, simple.so, that is compiled during the installation. - Checks for incorrect NeedsCompilation. Some packages have this flag, but nothing is compiled. E.g., reshape, analogueExtra, AGHmatrix... - Checks for execution flags. The execution bit is enabled in many, many files in many packages when it shouldn't (i.e., there's no shebang). An example that comes to mind: Javascript files under "inst" in shinyAce. - Checks for incorrect versions in dependencies. E.g., rtweet depends on magrittr >= 1.5.0, and abstractr depends on gridExtra >= 2.3.0. It should be 1.5 and 2.3 respectively. This may not be important on CRAN, because version comparisons still work in R, but this fails in other systems, such as RPM packaging. - Checks for top-level directories. I suppose there are some already in place, but e.g., adapr has a zero-length file called "data" in the sources. It seems that the installation command simply ignores it, but it shouldn't be there. Thanks for the already huge efforts to implement more thorough checks. Hope this helps for the task. Regards, -- I?aki ?car