john(a)laptop01:~/ciao_mongo$ ciaoc test.pl {ERROR: streams_basic:$open/3, arg 1 - system error: Permission denied} {Executable generation aborted} john(a)laptop01:~/ciao_mongo$
Yes, this message from the standalone compiler could certainly be more informative (we will look into that, it looks like an undetected side effect of the move to ISO errors).
Forgot to respond to this: messages fixed (development version). Please let us know if you have any other problems with this! Cheers, --Manuel H