Call these helpers to see the last deprecation warnings along with their backtrace:

  • last_warnings() returns a list of all warnings that occurred during the last top-level R command.

  • last_warning() returns only the last.

If you call these in the console, these warnings are printed with a backtrace. Use print(last_warnings(), simplify = level) to control the verbosity of the backtrace. The simplify argument supports one of "branch" (the default), "collapse", and "none" (in increasing order of verbosity).




# These examples are not run because `last_warnings()` does not # work well within knitr and pkgdown if (FALSE) { f <- function() invisible(g()) g <- function() list(h(), i()) h <- function() deprecate_warn("1.0.0", "this()") i <- function() deprecate_warn("1.0.0", "that()") f() # Print all the warnings that occurred during the last command: last_warnings() # Print only the last one: last_warning() # By default, the backtraces are printed in their simplified form. # Use `simplify` to control the verbosity: print(last_warnings(), simplify = "none") }