Improve error report when chunk fails

[cderv]

This closes #2215

• Optionally use rlang to add global handlers for traceback (using rlang::global_entrace()
• Add chunk name in brackets into the error report in addition to lines and file name

Created as a first draft for discussion, and to improve dealing with possible edge cases when we agree on #2215

cc @yihui @hadley

[cderv]

@lionel- I made the change to use withCallingHandlers(error = function(cnd) rlang::entrace(cnd)). Is doing that within the existing withCallingHandlers ok ? Is this done conform as you suggested ?

@hadley asking for another review as you may want to check this on your end

(Oh I can do only one reviewer at a time... sorry for the notification noise)

@yihui I believe this ok for you.

thanks

[cderv]

Thanks !

(In a future PR it'd be cool to use cli.r-lib.org/reference/links.html#files, so that the error message was clickable)

Yes this is tracked in #2153 - I added the doc there so that I can follow the recommandations

[lionel-]

@cderv

I made the change to use withCallingHandlers(error = function(cnd) rlang::entrace(cnd)). Is doing that within the existing withCallingHandlers ok ?

yup perfect!

[yihui]

I think this PR broke some learnr tests such as https://github.com/rstudio/learnr/blob/main/tests/testthat/test-exercise.R#L128

── Failure ('test-exercise.R:128:3'): render_exercise() returns envir_result up to error ──
exercise_result$parent inherits from 'rlang_error'/'error'/'condition' not 'simpleError'.
── Failure ('test-exercise.R:184:3'): evaluate_exercise() errors from setup chunks aren't checked by error checker ──
exercise_result$feedback$error inherits from 'rlang_error'/'error'/'condition' not 'simpleError'.
── Failure ('test-exercise.R:201:3'): evaluate_exercise() errors from user code are checked by error_checker ──
exercise_result$feedback$checker_args$last_value inherits from 'rlang_error'/'error'/'condition' not 'simpleError'.
── Failure ('test-exercise.R:222:3'): evaluate_exercise() errors from user code are checked by default error checker as a fallback ──
exercise_result$feedback$checker_args$last_value inherits from 'rlang_error'/'error'/'condition' not 'simpleError'.
── Failure ('test-exercise.R:461:3'): evaluate_exercise() handles default vs. explicit error check code ──
res$feedback$checker_args$last_value inherits from 'rlang_error'/'error'/'condition' not 'simpleError'.

I'm not sure what we should do about it (cc @gadenbuie).