Unfortunately, "parallel" is also a tool in moreutils, and moreutils version has a completely different args. I often have moreutils installed (for "errno" and

Unfortunately, "parallel" is also a tool in moreutils, and moreutils version has a completely different args. I often have moreutils installed (for "errno" and "ts" tools) so I cannot have GNU parallel installed at the same time. And even if you fix your PC, if you share your script and wrong parallel is installed, it will look like syntax errors in your script, instead of a missing package. This, and the obnoxious cite requirement, is why I recommend avoiding it. Use xargs -j for simple cases, and python scripts for a more complex ones. Parallel execution in python is pretty simple, and often requires no locks at all thanks to GIL.