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). In any case it appears that one of the files being compiled is not readable by the user that is running the compiler. Note that this can be your files (i.e., test.pl) or the ciao libraries (in the installation, which makes them readable by default). In any case-making them all readable should fix it.