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RalfJung opened this issue Jun 3, 2025 · 0 comments · Fixed by #141970
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Suggested workflow for vscode check-on-save can lead to surprisingly expensive check builds #141955

RalfJung opened this issue Jun 3, 2025 · 0 comments · Fixed by #141970
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A-contributor-roadblock Area: Makes things more difficult for new or seasoned contributors to Rust T-bootstrap Relevant to the bootstrap subteam: Rust's build system (x.py and src/bootstrap)

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@RalfJung
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RalfJung commented Jun 3, 2025 •
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With the stage 0 redesign, ./x check now (sometimes?) defaults to stage 1. If a downloaded rustc cannot be used, this command is quite expensive: it does a full rustc build, and then checks everything! That's not what users expect from a check build (which is supposed to be quick). It's also bad when you are on battery -- it's a nasty surprise when you realize that just opening vscode sucked up 8% of your battery as it did a full rustc build.

I don't know what the best fix here, but I think it is a hard requirement for the suggested check-on-save command that it never does an actual full compiler build. This was true with the old staging, and we should make sure it becomes true again.
@RalfJung RalfJung added the C-bug Category: This is a bug. label Jun 3, 2025
@rustbot rustbot added the needs-triage This issue may need triage. Remove it if it has been sufficiently triaged. label Jun 3, 2025
@RalfJung RalfJung mentioned this issue Jun 3, 2025
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@onur-ozkan onur-ozkan added T-bootstrap Relevant to the bootstrap subteam: Rust's build system (x.py and src/bootstrap) A-contributor-roadblock Area: Makes things more difficult for new or seasoned contributors to Rust and removed C-bug Category: This is a bug. needs-triage This issue may need triage. Remove it if it has been sufficiently triaged. labels Jun 3, 2025
@jyn514 jyn514 mentioned this issue Jun 5, 2025
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matthiaskrgr added a commit to matthiaskrgr/rust that referenced this issue Jun 5, 2025
@matthiaskrgr
Rollup merge of rust-lang#141970 - onur-ozkan:skip-stage1-std, r=Kobzol
9bd566c 
implement new `x` flag: `--skip-std-check-if-no-download-rustc`

One of our developers (`@RalfJung)` [reported](https://rust-lang.zulipchat.com/#narrow/channel/326414-t-infra.2Fbootstrap/topic/Surprising.20stages.20for.20check.20build.20after.20stage.20reorg/with/521925606)[#t-infra/bootstrap > Surprising stages for check build after stage reorg](https://rust-lang.zulipchat.com/#narrow/channel/326414-t-infra.2Fbootstrap/topic/Surprising.20stages.20for.20check.20build.20after.20stage.20reorg/with/521925606) that working on both the compiler and the library simultaneously with RA enabled is extremely difficult because checking library creates a heavy load on machines (by building stage1 compiler) on each modification. `--skip-std-check-if-no-download-rustc` flag is intended to reduce this heavy load on their IDE integration as much as possible.

Fixes: rust-lang#141955
@bors bors closed this as completed in cfe78d9 Jun 5, 2025
rust-timer added a commit that referenced this issue Jun 5, 2025
@rust-timer
Unrolled build for #141970
2c78a52 
Rollup merge of #141970 - onur-ozkan:skip-stage1-std, r=Kobzol

implement new `x` flag: `--skip-std-check-if-no-download-rustc`

One of our developers (``@RalfJung)`` [reported](https://rust-lang.zulipchat.com/#narrow/channel/326414-t-infra.2Fbootstrap/topic/Surprising.20stages.20for.20check.20build.20after.20stage.20reorg/with/521925606)[#t-infra/bootstrap > Surprising stages for check build after stage reorg](https://rust-lang.zulipchat.com/#narrow/channel/326414-t-infra.2Fbootstrap/topic/Surprising.20stages.20for.20check.20build.20after.20stage.20reorg/with/521925606) that working on both the compiler and the library simultaneously with RA enabled is extremely difficult because checking library creates a heavy load on machines (by building stage1 compiler) on each modification. `--skip-std-check-if-no-download-rustc` flag is intended to reduce this heavy load on their IDE integration as much as possible.

Fixes: #141955
github-actions bot pushed a commit to rust-lang/miri that referenced this issue Jun 6, 2025
@matthiaskrgr
Rollup merge of #141970 - onur-ozkan:skip-stage1-std, r=Kobzol
2ee131b 
implement new `x` flag: `--skip-std-check-if-no-download-rustc`

One of our developers (``@RalfJung)`` [reported](https://rust-lang.zulipchat.com/#narrow/channel/326414-t-infra.2Fbootstrap/topic/Surprising.20stages.20for.20check.20build.20after.20stage.20reorg/with/521925606)[#t-infra/bootstrap > Surprising stages for check build after stage reorg](https://rust-lang.zulipchat.com/#narrow/channel/326414-t-infra.2Fbootstrap/topic/Surprising.20stages.20for.20check.20build.20after.20stage.20reorg/with/521925606) that working on both the compiler and the library simultaneously with RA enabled is extremely difficult because checking library creates a heavy load on machines (by building stage1 compiler) on each modification. `--skip-std-check-if-no-download-rustc` flag is intended to reduce this heavy load on their IDE integration as much as possible.

Fixes: rust-lang/rust#141955
github-actions bot pushed a commit to rust-lang/rustc-dev-guide that referenced this issue Jun 9, 2025
@matthiaskrgr
Rollup merge of #141970 - onur-ozkan:skip-stage1-std, r=Kobzol
0c371e2 
implement new `x` flag: `--skip-std-check-if-no-download-rustc`

One of our developers (``@RalfJung)`` [reported](https://rust-lang.zulipchat.com/#narrow/channel/326414-t-infra.2Fbootstrap/topic/Surprising.20stages.20for.20check.20build.20after.20stage.20reorg/with/521925606)[#t-infra/bootstrap > Surprising stages for check build after stage reorg](https://rust-lang.zulipchat.com/#narrow/channel/326414-t-infra.2Fbootstrap/topic/Surprising.20stages.20for.20check.20build.20after.20stage.20reorg/with/521925606) that working on both the compiler and the library simultaneously with RA enabled is extremely difficult because checking library creates a heavy load on machines (by building stage1 compiler) on each modification. `--skip-std-check-if-no-download-rustc` flag is intended to reduce this heavy load on their IDE integration as much as possible.

Fixes: rust-lang/rust#141955
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implement new x flag: --skip-std-check-if-no-download-rustc onur-ozkan/rust
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