[beta-1.70] backport #12165

[weihanglo]

Beta backports:

• fix: pass -C debuginfo after weakening if explicitly set #12165
  • Adjusted a bit since TomlDebugInfo::None was not there in 1.70.0. It was a simple u32 0.

In order to make CI pass, the following PRs are also cherry-picked:

• Fix warning with unused mut #12065
• Remove useless drop of copy type #12136

[rustbot]

r? @epage

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[rustbot]

⚠️ Warning ⚠️

• Pull requests are usually filed against the master branch for this repo, but this one is against rust-1.70.0. Please double check that you specified the right target!

[weihanglo]

@bors try

[bors]

⌛ Trying commit cb0bdbb with merge dbfcbf4...

[weihanglo]

https://github.com/rust-lang/cargo/actions/runs/5057792442/jobs/9077009414?pr=12167

-Zbuild-std failed. This is going to be painful. The fix of build-std shouldn't be backported but without a backport we cannot bypass the CI pipeline. I guess the obvious way is running build-std only when the PR aims to merging into master. Let's see how to solve this.

[ehuss]

The fix of build-std shouldn't be backported but without a backport we cannot bypass the CI pipeline

Can you say why not? I would imagine backporting #12088 should be fine.

I guess the obvious way is running build-std only when the PR aims to merging into master. Let's see how to solve this.

It seems reasonable to stop running nightly tests on beta/stable. It might be a little tricky to do it correctly in CI due to the way bors works, so I'm not sure how that can be done.

[weihanglo]

The fix of build-std shouldn't be backported but without a backport we cannot bypass the CI pipeline

Can you say why not? I would imagine backporting #12088 should be fine.

libsysroot only exists in nightly right now. I didn't think about it much but I believe some stuff like library/sysroot directooy cannot be found on beta and it may fail something.

I guess the obvious way is running build-std only when the PR aims to merging into master. Let's see how to solve this.

It seems reasonable to stop running nightly tests on beta/stable. It might be a little tricky to do it correctly in CI due to the way bors works, so I'm not sure how that can be done.

Yeah I've tried but no luck. bors knows nothing about branches on rust-lang/cargo 😞.

[ehuss]

libsysroot only exists in nightly right now. I didn't think about it much but I believe some stuff like library/sysroot directooy cannot be found on beta and it may fail something.

The build-std tests are disabled on stable and beta, so I don't think it should be a concern. The only place they run is in Cargo's CI on the nightly builders, and those are always using the latest nightly. These tests don't run on rust-lang/rust, so it isn't a concern there.

[ehuss]

I think it might be a bit too late to get this into beta. It's not clear to me how likely it is that a project will run into this issue. If you think it is sufficiently rare, then this should probably be closed.

[weihanglo]

Yup sure. Given they already have some workaround I think it's fine just closing this.

Actually I was waiting for #12181. Still want it or something else to get landed.