You can run your program in the repl and :set -fbreak-on-error . You can get stack traces with access to variables via :set trace, but because of optimizations

You can run your program in the repl and :set -fbreak-on-error . You can get stack traces with access to variables via :set trace, but because of optimizations and lazy evaluation they are similarly jumbled as async code debugging. Haskell has some nice advantages like `:r` for reloading, similarly you can reload a dynamically linked binary and the old version is only unlinked after all references to it are gone. There is a significant difference to dynamic languages, though, because having different versions in memory leading to incompatible types would be a lot more common with a partial reloading workflow.