fix(ci): prepare.sh should install the toolchain

[pront]

Summary

This https://github.com/vectordotdev/vector/actions/runs/13635254034/job/38112313325 fails on master.

Change Type

• Bug fix
• New feature
• Non-functional (chore, refactoring, docs)
• Performance

Is this a breaking change?

• Yes
• No

How did you test this PR?

Does this PR include user facing changes?

• Yes. Please add a changelog fragment based on our guidelines.
• No. A maintainer will apply the "no-changelog" label to this PR.

Checklist

• Please read our Vector contributor resources.
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References

Ref: rust-lang/rustup#4217

[pront]

CI seems happy now: https://github.com/vectordotdev/vector/actions/runs/13636321013/job/38115894786

[datadog-vectordotdev]

Datadog Report

Branch report: pront/fix-rust-prepare
Commit report: 715f989
Test service: vector

✅ 0 Failed, 7 Passed, 0 Skipped, 25.44s Total Time

[jszwedko]

I think the latest failure is because you are using sudo to add the target resulting in the local user not being able to use it.

[pront]

With Rustup 1.28 (https://blog.rust-lang.org/2025/03/02/Rustup-1.28.0.html), rustup will no longer automatically install the active toolchain if it is not installed.

Also, rust-lang/rustup#4217 (related to the previous fix)

[jszwedko]

Aaaah, I see. Should we add this to the bootstrap or prepare script instead?

[pront]

It is already part of the prepare script. Not for the bootstrap, because that script is executed with sudo -E and we want an installation for non-root users too.

[jszwedko]

I'm confused why you had to add it here, too, then since it is right after the prepare.sh script which also runs it?

[pront]

Are you referring to https://github.com/vectordotdev/vector/blob/master/.github/workflows/k8s_e2e.yml#L104?

I basically followed the errors and added it. The prepare.sh script runs rustup show active-toolchain || rustup toolchain install and that doesn't install the x86_64-unknown-linux-gnu target.

[jszwedko]

🤔 I think I'm getting turned around but I'd suggest that we try to move the direct commands into one of the bootstrap or prepare scripts to DRY it up rather than having it specified in different workflows. In the k8s_e2e case it has:

      - run: bash scripts/environment/prepare.sh
      - run: ~/.cargo/bin/rustup target add x86_64-unknown-linux-gnu

So here it seems like you could move the target add to the prepare.sh script.

[pront]

Discussed offline, we can leave as is for now because it is a special target that is not required by all jobs.

Also, per https://x.com/rustlang/status/1896954416101732709?s=46&t=x164rvMb1LGppUzviMH60w we might be able to just delete all these one-off target add lines.