[FR] Navigate the callstack in debug-prompt eval_code

[timholy]

It would be nice to be able to move up and down the call stack in a manner that allows commands you enter at the debug prompt to reflect that scope. What about replacing the current Callstack with a popup menu?

[pfitzseb]

What do you think about making the stack level clickable? That would then also change the prompt to e.g. 3|debug>.
I'm not entirely sure how this would interact with stepping though -- changing to a different callstack level should presumably move the stepper widget to the right place, but you couldn't actually step on from there (that should only be possible from the lowest level).

[timholy]

Right. Before you step you call leaf(frame), if your internal storage of frame reflects what the user clicked.

[pfitzseb]

Implemented in JunoLab/atom-ink@ba17078, JunoLab/Atom.jl@ea9c1f1, and JunoLab/atom-julia-client@9ad603d.