But that’s not the same thing at all. If you’re debugging an exception in Java, you cannot continue execution as if the exception had not been thrown at all. With Common Lisp’s condition system you can.

Umm.. you can throw an exception, you can return to previous call frame, you can reload modified classes. If you want unlimited code modification, you can use dcevm https://github.com/dcevm/dcevm

https://www.jetbrains.com/help/idea/altering-the-program-s-e...

The question was whether you can debug a live service while it's handling live traffic. Not whether you can fix it. Java can definitely do the former, and definitely can't do the latter.

my question specifically was which languages/runtimes allow you to actually make changes to the code in a live process without restarting it.

Your question moved the goalposts. Making change to a running system wasn't part of db48x's claim to which dleslie responded. It was explicitly excluded, in fact.

ok, fair, but what i am asking about is a feature of common lisp (and smalltalk or pike), so i didn't pay attention to the exclusion. that was not deliberate. my bad. (maybe you could say i moved the goalpost back to the original topic)