Better labelling when you are debugging an app

[djacobs7]

When you go to debug an app, it seems to create a fork of the livebook. Frequently, I will start an app, click on 'debug', and then start editing the livebook. Then, I will eventually find my way back to the original livebook, (perhaps to relaunch the app with my new changes ) and find that all my changes are gone, because I was editing the 'debug' livebook, and not the one that I started with.

It may be helpful if there was some kind of visual indicator that I was in debug mode, and my changes weren't going to persist.

[jonatanklosko]

On Livebook v0.10.0 you should see a message when entering the debug session. Other than that, you click the "App" icon in sidebar and it will tell you if you're debugging a running app (which you can use as an indicator when in doubt).