How to warn users about the following problem? xcode updated on my computer; needed to do some stuff to get stan working

andrewgelman · September 25, 2019, 2:48am

Hey, so I was trying to run Stan and it didn’t work. Luckily for me, I was running it in Markdown and it gave me the helpful error message that I needed to do “sudo xcodebuild - license”. Then I remembered that my Mac had auto-updated Xcode recently.

I went into Terminal, typed “sudo xcodebuild - license”, and followed the instructions. It worked!

Anyway, I suspect this will happen to other users who, like me, will be surprised to have this problem, but, unlike me, won’t know what to do.

I’m not sure how to warn people about this; maybe someone has an idea?

bgoodri · September 25, 2019, 2:58am

Did you get a message from RStan

github.com

stan-dev/rstan/blob/develop/rstan/rstan/R/rstan.R#L124


}


# check for compilers
if (.Platform$OS.type != "windows") {
  CXX <- get_CXX()
  if (!is.null(attr(CXX, "status")) || nchar(CXX) == 0) {
    WIKI <- "https://github.com/stan-dev/rstan/wiki/RStan-Getting-Started"
    warning(paste("C++ compiler not found on system. If absent, see\n", WIKI))
  }
  else if (grepl("69", CXX, fixed = TRUE))
    warning("You may need to launch Xcode once to accept its license")
} else CXX <- "g++"


model_cppname <- stanc_ret$model_cppname 
model_name <- stanc_ret$model_name 
model_code <- stanc_ret$model_code 
inc <- paste("#define STAN__SERVICES__COMMAND_HPP",
             # include, stanc_ret$cppcode,
             if(is.null(includes)) stanc_ret$cppcode else
               sub("(class[[:space:]]+[A-Za-z_][A-Za-z0-9_]*[[:space:]]*: public prob_grad \\{)",
                   paste(includes, "\\1"), stanc_ret$cppcode),

or from RStudio?

andrewgelman · September 25, 2019, 3:17am

The message was from Rstudio, in the Markdown window. I can’t reconstruct it because the window got overwritten after I recompiled the model.

bgoodri · September 25, 2019, 3:50am

I think you would have gotten a similar message from RStan eventually.

torkar · September 25, 2019, 6:22am

Happened to me too recently. When I ran it in RStudio I saw the message from RStan and it hit me: I had updated Xcode and needed to say ok to the license agreement :)

andrewgelman · September 25, 2019, 12:27pm

Maybe what we need is a Troubleshooting page for rstan, a wikipage with a list of common problems and solutions.

I created such a page:

Maybe people could add more items to it? Then we could link to that page from the main Rstan page.

I imagine we might also want to have similar pages for Stan, PyStan, rstanarm, and brms?

Bob_Carpenter · September 27, 2019, 5:24pm

I love this kind of attention to detail on install—it’s super helpful for users, as Andrew just demonstrated!