R Debugging - Unable to see which line generates a warning message (Shiny)

Question

Is there a way to get Rstudio to say which line of the source file is generating a warning message? Right now, it just prints a message, and I'm lost as to what causes the problem.

In Rstudio, this menu option is checked: Debug> Error> Error inspector

But this does not help, perhaps because these are warnings, not errors? Ideas?

Answer 1

First turn on the display of warnings using the options(warn=1) command. Then you can start it by clicking the "Source" or "Source with echo" button (see the figure below). You can see error / warning messages when any line with errors / warnings is executed.