I don't remember getting any useful error message, but I've been using Kotlin for 3 years now, so I might not remember correctly. Can you post a stacktrace of what you're referring to?
as stated in another comment, you get :
s exception:
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String java.lang.Integer.toString()' on a null object reference
the name of the method causing the crash (toString in that sample) + the line number and location thanks to the stacktrace (although in some rare case it is 100% accurate, but still pretty close, maybe that's due to runtime inlining) and it is very trivial to know where the exception comes from.
the name of the method causing the crash (toString in that sample) + the line number and location thanks to the stacktrace (although in some rare case it is 100% accurate, but still pretty close, maybe that's due to runtime inlining) and it is very trivial to know where the exception comes from.