Your example does not apply in my case, because in your case, the program would not even start to run. My problem applies to a program, which is already running (i.e. already produced output). When eval finds a syntax error during compile, eval says:

Incidentally, when rechecking my code, I indeed found a bug, in that I don't properly handle the case when eval returns undef, so maybe this explains what I have seen: eval *does* return, but returns undef, and my program crashes when it uses that undef value. I will fix this, to be on the safe side.