Warn when tracing is enabled with big-bang?

[maueroats]

Racket 8.4

Language -> Choose Language -> Show Details -> [X] Enable tracing

Would it be possible for big-bang to generate a warning if run when the "Enable tracing" option is selected under Output Syntax?

The error caused by my (non-minimal) sample is currently:

 expr-iterator: unknown expression (phase #false): #<syntax:/usr/local/share/racket/collects/racket/private/kw.rkt:1392:76 (#%variable-reference proc>6)> (#%variable-reference proc>6)

This might not be worth pursuing, since there is a clear indication that the language is not standard.

However, turning on tracing is nice for debugging when working with lists / recursive functions, so it's possible for students to end up with tracing enabled "by accident".