What does “This command require keg argument” mean?

Question

I want brew rm mtr and its deps, so I do

brew rm mtr brew rm $(join <(brew leaves) <(brew deps mtr)) 

But he says This command requires a keg argument . What is the barrel argument?

Thanks.

Answer 1

I don’t think the team is doing what you think.

Those <redirects do not do what you think, and therefore the brew command executed is executed

 brew rm 

This requires an argument.

I like trying to use a connection without a temporary file. After looking at the man page, I am sure you cannot do this.

Try the following:

 brew leaves > leaves brew rm $(brew deps mtr | join leaves -)