I don't think what you say is correct. See: https://stackoverflow.com/questions/69065097/why-java-stack-traces-are-generated-when-exceptions-are-constructed htt

I don't think what you say is correct. See: https://stackoverflow.com/questions/69065097/why-java-stack-traces-are-generated-when-exceptions-are-constructed https://stackoverflow.com/questions/69065097/why-java-stack-... Hence it works in Scala (and also Java) without throwing Edit: maybe what you meant to say is that the stack is only unwinded at the time of generating the stacktrace and not when the exception is created? Which is true and a good thing since it's expensive to create it.