Probably folks have seen the crash message in REPL:

That entry seems to have slain the compiler.  Shall I replay
your session? I can re-run each line except the last one.
[y/n]
Abandoning crashed session.

I had a version once that asked [y/n/q] to quit directly, and save keystrokes. But now I wonder, is it better just to say, Type :replay to re-run each line except the last. I have a separate idea for :replay -all -Xprint:typer to also replay the last line.
That means if they don't replay, then reset before continuing.

Retronym: What we really ought to do is start a new compiler with the compilation products of the crashed compiler on the classpath. Should be no need to replay.
The tab completion works in this way every time you hit TAB.

Also Retronym: We could even have a mode of the REPL that uses a new Global for every line.