GNU parallel not working at all

Question

I have been trying to use GNU parallel for some time, but I have never been able to get it to function at all!

For example, running (in a non-empty directory!):

Answer 1

For me it was same issue but different problem. Just running parallel command was exiting silently. Also parallel --version was saying invalid option error. In my Path there was just one parallel executable binary but still it was not detecting.

I was able to fix it as below:

1. Run whereis parallel. This gives all the paths where executables named parallel is present. For my case there was just one path /usr/local/bin/parallel. Running using this path works just fine.
2. You can add an alias for this in ~/.bashrc or ~/.zshrc file like alias parallel='/usr/local/bin/parallel'

And now parallel works like charm.

dev-dsk % parallel --version         
GNU parallel 20190322
Copyright (C) 2007-2019 Ole Tange and Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later 
This is free software: you are free to change and redistribute it.
GNU parallel comes with no warranty.