Move needless_collect to nursery

[sophiajt]

Please write a short comment explaining your change (or "none" for internal only changes)

changelog: [needless_collect]: Move needless_collect to nursery (Now allow-by-default)

After chatting with a few folks, it seems like needless_collect is giving false positives pretty regularly (https://github.com/rust-lang/rust-clippy/issues?q=is%3Aissue+is%3Aopen+needless_collect). We're big supporters of clippy in Nushell, and it's one of the passes we require for CI, but we've had to disable this particular lint. Perhaps it should be moved to the nursery until it's improved?

(apologies if this isn't the right approach to disabling a lint by default. I tried to follow the idea I saw other PRs doing in the past)

[rust-highfive]

Thanks for the pull request, and welcome! The Rust team is excited to review your changes, and you should hear from @Manishearth (or someone else) soon.

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[Manishearth]

cc @rust-lang/clippy

we probably can write up a plan for what it would take to enable it again

[Manishearth]

(fwiw the typical procedure is to open an issue first and list prior issues and discussions, but this works too)

[sophiajt]

For the tests failing in CI, should these tests be skipped by default, or is there another procedure for them?

[Jarcho]

You'll need to run cargo dev update_lints and add those changes.

[sophiajt]

@Jarcho - I ran cargo dev update_lints, but it didn't change any files. Is there a step I need to do before that step?

[flip1995]

With #9541 lint re-categorizing got really simple it seems. Doesn't even require cargo dev update_lints anymore. Great work @Alexendoo !

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@jntrnr The needless_collect_indirect.rs UI test doesn't have a #![warn(clippy::needless_collect] attribute, because the lint was a warn-by default lint before. Just add this attribute to the top of the test file and run cargo uitest followed by cargo dev bless and this should be good.

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we probably can write up a plan for what it would take to enable it again

There are many issues open for this lint with a pretty detailed description of some significant FPs. I would say the plan to enable this lint again would be to fix those first. Some of them will be quite hard though, because they will involve predicting borrowing rules...

[Jarcho]

Didn't notice that one. Yay for less merge conflicts.

[sophiajt]

@flip1995 - thanks, that fixed.

[Manishearth]

There are many issues open for this lint with a pretty detailed description of some significant FPs. I would say the plan to enable this lint again would be to fix those first. Some of them will be quite hard though, because they will involve predicting borrowing rules...

Yeah I'm basically thinking we file an issue listing all the existing bugs, and also saying the general area of things that ought to be explored for further bugs before un-nurserying it.

[xFrednet]

I favor of this move, the lint produces some FPs in another project of mine as well :)

[Manishearth]

Everyone seems on board, I'm merging

@bors r+

[bors]

📌 Commit 4f3fb00 has been approved by Manishearth

It is now in the queue for this repository.

[bors]

⌛ Testing commit 4f3fb00 with merge 213003b...

[bors]

☀️ Test successful - checks-action_dev_test, checks-action_remark_test, checks-action_test
Approved by: Manishearth
Pushing 213003b to master...