Consider using nushell instead of bash in tests?

[mightyiam]

Just thinking out loud here and not very concretely, but I'm looking at what seems to be well-written bash in #4311 and still wishing I wasn't looking at bash. I'm just a noob at nushell, really, but so far it has been such a pleasant experience compared with other shells.

[khaneliman]

Not sure there's enough benefits to switching up to something so new and prone to breaking. I've had to disable it in my config numerous times due to the package breaking upstream and they don't have good linting / formatting tooling, yet.

[MattSturgeon]

I'm definitely in favour of avoiding bash for anything non-trivial. Typically, we've reached for python for non-trivial tests and derivations.

I don't think this is a high priority, though. And I'd need some convincing to accept nushell, especially as I've not worked with it before.

[siph]

Nushell isn't stable yet. I generally use it in my projects but I pin nushell to a version to avoid breaking syntax changes (although they are much less frequent now).

Sidenote: there used to be a cool tool called nuenv that would change the stdenv from bash to nushell.