In case a search engine leads someone with the same issue here, I am documenting the point I reached:
I can reproduce the issue with a small example when forcing R to not load any package at startup time (using an Renviron file): ``` package <- "utils" lib.loc <- "<fill this according to your R install>" ns <- loadNamespace(package, lib.loc) ``` The code path goes through `registerS3methods(nsInfo$S3methods, package, env)` and there to: ``` if (methods::is(genfun, "genericFunction")) ``` The evaluation of `methods::is` reaches the line triggering the error as `.identC(class1, class2)` and `.identC(class2, "ANY")` both return `NA` and `NA || NA` is not defined: ``` > if (NA || NA) { cat("here\n") } Error in if (NA || NA) { : missing value where TRUE/FALSE needed ``` As I understand it `.identC()` should never return `NA`, and if the case this would mean that R itself is an unstable state (something at the C level that should not have happened has happened) but this was not caught earlier. [[alternative HTML version deleted]] ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel