GNU Parallel – Why Does Parallel Fail Silently and How to Fix It

In a larger script to post-process some simulation data I had the following line:

parallel bnzip2 -- *.bz2

Which, if I understand parallel correctly (and I may not), should run n-core threads of the program over all files with the listed extension. You may notice that I misspelled the command bunzip2. I would expect a warning or error message here, but it fails silently. Is this intended? How do I not get bit by this in the future?

Update:

It is possible that I have a different parallel installed than I think I do:

> parallel --version`


parallel: invalid option -- '-'
parallel [OPTIONS] command -- arguments
    for each argument, run command with argument, in parallel
parallel [OPTIONS] -- commands
    run specified commands in parallel

A man page of parallel on my system gives:

 parallel(1)                                                        parallel(1)
NAME
       parallel - run programs in parallel
....
AUTHOR
   Tollef Fog Heen

Which seems this is not the GNU version.