Error! Not more than one entry file/directory is expected

I'm trying to build a cli tool with the following command

npx pkg . -d --targets node14-macos-x64 -- output bin/macos/metaplex

Which gives me the error in the title.

Error! Not more than one entry file/directory is expected

Any idea why I'm getting this error and unable to build the cli tool in the output folder specified?

Thanks for the help. :)