Introduce `env` command to manage environments

[carstenbauer]

It would be nice to have a command for listing all environments. Currently the best one can do is gc, which will output a list at the top. Also, autocompletion for environment names when doing activate would be nice.

[00vareladavid]

At the very least: adding tab completion for pkg> activate --shared should be straightforward.

[carstenbauer]

It feels strange to me that julia manages environments in a somewhat hidden manner. It keeps a list of all active manifests (environments), as can be seen by gc, but doesn't let me see the list easily (this issue), doesn't have autocompletion (this issue), and also doesn't let me remove environments without deleting them on disk.

Why not make this more transparent?

activate could add an environment to the list, listenvs could list all known environments, and rmenv could remove an environment. The user would have more control over what julia tracks.

[fredrikekre]

It seems iffy that Pkg should be able to remove environments. What should be deleted? The Project.toml and Manifest.toml files?

[carstenbauer]

Nothing should actually be deleted. Julia should just stop keeping track of that particular environment (manifest). I.e. the manifest should be removed from the list that I see when I do gc.

[carstenbauer]

I have this use case in mind: My collaborator sends me a project folder. I wanna check it out so I do activate . and instantiate. However, from that point on I have the projects dependencies installed and can't free them up without deleting the whole project folder.

Why can't the user tell Julia to ignore this environment again? I mean it also didn't track it automatically when I created it on my disk. Only when I did activate it at some point.

[fredrikekre]

How about

(v1) pkg> listenv
[1] `/home/fredrik/.julia/environments/v0.7/Manifest.toml`
[2] `/home/fredrik/.julia/environments/v1.0/Manifest.toml`
[3] `/home/fredrik/TestProject/Manifest.toml`

(v1) pkg> activate 3

(TestProject) pkg>

[carstenbauer]

Looks great!

[carstenbauer]

It seems iffy that Pkg should be able to remove environments. What should be deleted? The Project.toml and Manifest.toml files?

Maybe, to avoid the confusion, the command to remove an environment from the list should be called untrack or similar rather than rmenv.

[StefanKarpinski]

What about an env command and an env list subcommand?

[carstenbauer]

What about an env command and an env list subcommand?

And env untrack? Sounds great to me.

Although I'd love to make a PR to get this merged soonish, I feel I'm not the right person for this. So hopefully someone else will give it a shot soon. I'd appreciate it!

[00vareladavid]

I renamed the issue to focus on env. #834 exists for tab completion on activate (which should be made a lot simpler by #839).

[carstenbauer]

Is someone working on this? I'd love to see this in 1.1 and I heard feature freeze is mid Nov.