Support globally activating local packages

[munificent]

Right now, "pub global activate" only supports hosted packages. This means you can't globally activate a package that hasn't been published. That makes it really hard to develop packages intended to be globally activated: you can't test them until after you've published them.

To solve that, you should be able to activate a local package. I'm thinking, from within the root directory of a package, you can do:

$ pub global activate --current

This will make that package globally available. It will make that a live link: any changes to the current package will be immediately reflected by pub global run. (In order to get new executables on your PATH, you may have to reinstall the package, though.)

[nex3]

This seems like a less-general version of issue #19902. Isn't this just activating a path package?

[munificent]

I suppose so. Path dependencies will still need special sauce here because it's important to handle non-cached packages differently from cached ones. I think the common use case is wanting to activate the package you're currently hacking on, so it seemed reasonable to have a command that worked off the cwd.

[nex3]

I don't think activating a current package is going to be that common. It's easy to test executables in the current package locally, so as long as users have faith that "pub global activate" does what it's supposed to I don't think they'll take the extra step of globally installing something themselves very often.

It's also not too difficult to write "pub global activate --source path .".

[munificent]

--source path is a bit gratuitous. How about just:

pub global activate --path ...

[nex3]

Sure.

[munificent]

On further thought, my suggestion doesn't work. It would allow weird stuff like:

pub global activate foo --path
pub global activate --git foo --path

The original suggestion makes more sense. Given that, I'm going to close this bug out and just start the one for supporting other sources.

---

Added Invalid label.