Emacs recursive editing is magical. If your code crashes, you can browse and edit the code whilst the debugger is active!
miniblog.
Related Posts
Which programming languages follow the "cathedral" design philosophy, where they provide most of: the runtime, stdlib, debugger, LSP, test harness, code formatter and package manager?
Go, Dart and Smalltalk are the closest I can think of.
Rust's RFC 3191 will let libraries package debugger scripts so you get a better experience when using gdb or windbg:
https://www.youtube.com/watch?v=0DLdQ6yb7h8 is a really accessible introduction to programming workflows with Sly for Common Lisp.
The notion of 'stickers' is novel to me: you mark places in the code where you want to remember values (essentially tracing) or pop to a debugger (breakpoints).