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Remove unnecessary stage2 host builds from cross-compiled dist builders #145874

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Merged
merged 2 commits into from
Aug 26, 2025
Merged

Remove unnecessary stage2 host builds from cross-compiled dist builders #145874

merged 2 commits into from
Aug 26, 2025
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Kobzol
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@Kobzol Kobzol commented Aug 26, 2025

This is a repeated regression (#138004, #138123) that was reintroduced in #145472. I thought that we have a test for it, but alas, the "correct" test required --disable-docs. I added the test in this PR, and re-added the dist::Std build optimization that solves this.

r? @jieyouxu

@rustbot rustbot added S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. T-bootstrap Relevant to the bootstrap subteam: Rust's build system (x.py and src/bootstrap) labels Aug 26, 2025
jieyouxu
jieyouxu approved these changes Aug 26, 2025
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Oof, thanks

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@bors r+ rollup=never

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bors commented Aug 26, 2025

📌 Commit c7f90c1 has been approved by jieyouxu

It is now in the queue for this repository.

@bors bors added S-waiting-on-bors Status: Waiting on bors to run and complete tests. Bors will change the label on completion. and removed S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. labels Aug 26, 2025
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Kobzol commented Aug 26, 2025

This is causing some unnecessary builds also on dist builders with docs (because dist docs steps unnecessarily build stage 2 rustc). I'll fix that with a more general approach later, once this lands.

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jieyouxu commented Aug 26, 2025 •
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Looking at the queue, since it's rather tame, let's bump this to p=5.

@bors p=5 (unnecessary builds)

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bors commented Aug 26, 2025

⌛ Testing commit c7f90c1 with merge 5ab6924...

hkBst
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src/bootstrap/src/core/build_steps/dist.rs
// Normally, to build stage N libstd, we need stage N rustc.
// However, if we know that we will uplift libstd from stage 1 anyway, building the stage N
// rustc can be wasteful.
// In particular, if we do a cross-compiling dist stage 2 build from T1 to T2, we need:
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@hkBst hkBst Aug 26, 2025 •
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Does 'T' stand for target? I suggest spelling it out whatever it is. Alternatives: machine, arch(itecture)

hkBst
hkBst reviewed Aug 26, 2025
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src/bootstrap/src/core/builder/tests.rs
// Enable dist cranelift tarball by default with `x dist` if cranelift is enabled in
// `rust.codegen-backends`.
/// Simulates e.g. the powerpc64 builder, which is fully cross-compiled from x64, but it does
/// not build docs. Crutically, it shouldn't build host stage 2 rustc.
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Crucially or Critically?

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Haha :D Thanks, I'll fix it in a followup PR.

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bors commented Aug 26, 2025

☀️ Test successful - checks-actions
Approved by: jieyouxu
Pushing 5ab6924 to master...

@bors bors added the merged-by-bors This PR was explicitly merged by bors. label Aug 26, 2025
@bors bors merged commit 5ab6924 into rust-lang:master Aug 26, 2025
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@rustbot rustbot added this to the 1.91.0 milestone Aug 26, 2025
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What is this? This is an experimental post-merge analysis report that shows differences in test outcomes between the merged PR and its parent PR.

Comparing 4356e83 (parent) -> 5ab6924 (this PR)

Test differences

Show 7 test diffs

Stage 0

  • core::builder::tests::snapshot::dist_all_cross: pass -> [missing] (J0)
  • core::builder::tests::snapshot::dist_all_cross_extended: [missing] -> pass (J0)
  • core::builder::tests::snapshot::dist_all_cross_extended_no_docs: [missing] -> pass (J0)

Additionally, 4 doctest diffs were found. These are ignored, as they are noisy.

Job group index

Test dashboard

Run

cargo run --manifest-path src/ci/citool/Cargo.toml -- \
    test-dashboard 5ab69249f36678c0a770a08d3d1b28a8103349ff --output-dir test-dashboard

And then open test-dashboard/index.html in your browser to see an overview of all executed tests.

Job duration changes

  1. dist-apple-various: 5477.2s -> 4224.8s (-22.9%)
  2. dist-ohos-x86_64: 5338.3s -> 4195.8s (-21.4%)
  3. dist-ohos-armv7: 5023.5s -> 4045.7s (-19.5%)
  4. dist-riscv64-linux: 5929.9s -> 4790.4s (-19.2%)
  5. dist-s390x-linux: 6032.7s -> 4950.6s (-17.9%)
  6. aarch64-apple: 5109.4s -> 6024.4s (17.9%)
  7. dist-aarch64-windows-gnullvm: 5473.1s -> 4498.1s (-17.8%)
  8. dist-armhf-linux: 5919.6s -> 4894.4s (-17.3%)
  9. dist-loongarch64-musl: 6069.7s -> 5062.2s (-16.6%)
  10. dist-powerpc-linux: 6006.4s -> 5014.1s (-16.5%)
How to interpret the job duration changes?

Job durations can vary a lot, based on the actual runner instance
that executed the job, system noise, invalidated caches, etc. The table above is provided
mostly for t-infra members, for simpler debugging of potential CI slow-downs.

@Kobzol Kobzol deleted the fix-dist-builds branch August 26, 2025 15:14
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Finished benchmarking commit (5ab6924): comparison URL.

Overall result: no relevant changes - no action needed

@rustbot label: -perf-regression

Instruction count

This benchmark run did not return any relevant results for this metric.

Max RSS (memory usage)

Results (primary 2.3%, secondary -3.0%)

A less reliable metric. May be of interest, but not used to determine the overall result above.

mean range count
Regressions ❌
(primary)		 2.3% [2.3%, 2.3%] 1
Regressions ❌
(secondary)		 - - 0
Improvements ✅
(primary)		 - - 0
Improvements ✅
(secondary)		 -3.0% [-3.9%, -1.9%] 4
All ❌✅ (primary) 2.3% [2.3%, 2.3%] 1

Cycles

Results (primary -2.2%, secondary 2.1%)

A less reliable metric. May be of interest, but not used to determine the overall result above.

mean range count
Regressions ❌
(primary)		 - - 0
Regressions ❌
(secondary)		 2.9% [2.1%, 3.4%] 5
Improvements ✅
(primary)		 -2.2% [-2.2%, -2.2%] 1
Improvements ✅
(secondary)		 -2.2% [-2.2%, -2.2%] 1
All ❌✅ (primary) -2.2% [-2.2%, -2.2%] 1

Binary size

This benchmark run did not return any relevant results for this metric.

Bootstrap: 468.126s -> 466.377s (-0.37%)
Artifact size: 391.18 MiB -> 391.17 MiB (-0.00%)

@Kobzol Kobzol mentioned this pull request Aug 26, 2025
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