Yes, it was mentioned in the post: you normally get prompted not just when there's a breakpoint, but when your code calls something that doesn't yet exist, for

Yes, it was mentioned in the post: you normally get prompted not just when there's a breakpoint, but when your code calls something that doesn't yet exist, for example, or try to access a non-defined variable [1]... you have the option to "fix" the issue and continue from the same point, continue with a different value, or just let it crash... and there's stuff like profiling and de-compiling [2] which are all available directly from the REPL as well. [1] https://lispcookbook.github.io/cl-cookbook/debugging.html https://lispcookbook.github.io/cl-cookbook/debugging.html [2] https://lispcookbook.github.io/cl-cookbook/performance.html https://lispcookbook.github.io/cl-cookbook/performance.html