Pkg.jl: Feature request: easy "throw away" environments

[nickrobinson251]

Would it be nice if we had a julia --project=@tmp command (syntax TBD) for creating a "throw away" environment whcih exists only for the duration of the repl session?

E.g. operates in a tmp directory and automatically deletes /Project.toml and / Manifest.toml afterwards; so julia --project=@tmp again gives a new "throw away" environment.

Use case:

• Not editing any specifc package, so don't want julia --project=@.,
• Want to test something out, e.g. try reproduce a bug report
• Load julia and inevitably end up adding packages, e.g. the bugged package,
• Your "base" v1.1 environment ends up having tons of packages <-- something we might wish to avoid.

[nickrobinson251]

workaround suggested by @fredrikekre on slack:
julia --project=(mktemp -d) (fish) or
julia --project=$(mktemp -d) (sh)

[KristofferC]

I don't really think there needs to be a command line option for this. It should be enough that Pkg has some easy way of activating the temp env.

[KristofferC]

Why close, would still be nice to have it available in Pkg?

[oxinabox]

I still want this very regularly.

At least 4 timed in the last 2 days.