Situation

A user wants to change their CRAN repo, and goes to Tools > Global Options > Packages. If there are any upstream .Renviron, .Rprofile, or Rprofile.site configurations setting the CRAN repo, a notification is on display on the Package Management tab stating "CRAN repositories modified outside package preferences." If the user makes a change within this settings dialog, the repository will not be respected because of the upstream configuration.

This message is confusing, does not provide the user with complete information, and users can still make modifications to their preferences though it will have no effect, leading to confusion.

Suggested Improvements

1. Clarify message. Replace "CRAN repositories modified outside package preferences" with "CRAN repositories set as <rOptions.rCRANUrl> by <source>." This information is available here:

   rstudio/src/cpp/session/SessionMain.cpp

   Line 2430 in bdd5a2b

   LOG_INFO_MESSAGE("Set CRAN URL for session to '" + rOptions.rCRANUrl + "' (source: " +

2. Prevent the user from making meaningless changes. If the RStudio preferences are being overridden by an upstream configuration, disable the input window for modifying the CRAN repo.
3. Provide helpful information. If the user cannot change the settings using this window, tell them how they can change it. A pointer to a user-level or project-level .Renviron or .Rprofile would do the trick.