Currently, if an expectation fails with an exception (other than a FailureException), that exception will be caught and its message and stack trace will be printed. However, the actual type of the exception will not be reproduced. This can make a large number of exceptions very difficult to debug, given that it is standard practice to describe the exception entirely by the type and leave the message null (e.g. NullPointerException, StackOverflowError). Some other exceptions can also be difficult to debug even when their messages are non-null (e.g. IllegalArgumentException).

Such exceptions (when caught by specs) should be printed with their types, message and stack trace entirely intact. As mentioned, this is very-nearly the current behavior, but lacking the type.

fixed in 1.4.4-SNAPSHOT. Please confirm if it's ok with you. Thanks.