Re-factor argument parsing so that options shared by multiple commands aren't duplicated.

[tomprince]

This might involve some clever refactoring of the docopt definitions, or it might involve porting to something like clap.

I know @matklad has looked into this.

[tomprince]

Previous discussions:

• Add --exclude flag #4031 (comment)
• Add --exclude flag #4031 (comment)

[tomprince]

I'm going to investigate porting things to clap.

[alexcrichton]

👍

[matklad]

I'm going to make another stab at it :)

[dwijnand]

Fixed by #5152?

If you take the --feature option as an example you just need arg_features from command_prelude.

Look ma, no behaviour duplication!
https://github.com/search?q=repo%3Arust-lang%2Fcargo+arg_features&type=Code

[matklad]

Indeed, thanks @dwijnand