Consolidate stage directories and group logs in bootstrap

[Kobzol]

My post-stage-0-redesign bootstrap fixes aren't done yet, but I think that enough steps have been migrated to the new system that it makes sense to actually modify the directories on disk, and what gets printed when bootstrap runs, so that it actually corresponds to the new system. Before, the printed stages didn't always make sense.

This PR:

• Fixes the numbering of stageN directories in the build directory. It was not corresponding to the correct stages before; notice that I did not modify bootstrap/README.md, as it was essentially describing what happens after this PR (first commit). This means that stageN-<foo> now actually corresponds to <foo> (e.g. rustc or tools) that is stage N. Before in some cases it means that it was built with the stage N compiler. So for example stage0-rustc became stage1-rustc.
• Unifies all steps that output a build group to use the Builder::msg method. It's probably not the final stage, and some of the test steps might not be fully accurate yet, because I didn't fix test step numbering yet, but I think that it's a clear improvement from before, and now that everything uses the same method, we can easily make changes across the board, to ensure that it stays unified (second commit).

r? @jieyouxu

try-job: dist-x86_64-msvc
try-job: dist-x86_64-linux

[jieyouxu]

Looks good, tiny nits, r=me after.

[jieyouxu]

@rustbot author

[Kobzol]

Resolved review remarks. I would bump the priority of this, because it will be very conflict-prone with anything done in bootstrap.

[jieyouxu]

Thanks

[jieyouxu]

@bors r+ rollup=5 (conflicts with other bootstrap work, conflict-prone)

[bors]

📌 Commit f7defc0 has been approved by jieyouxu

It is now in the queue for this repository.

[jieyouxu]

Aaa
@bors p=5 rollup=never

[bors]

⌛ Testing commit f7defc0 with merge 5e2003d...

[bors]

💔 Test failed - checks-actions

[Kobzol]

@bors try

[rust-bors]

☀️ Try build successful (CI)
Build commit: 6f046d0 (6f046d0222ccb364b63d9ce259d40e6494353539, parent: d9dba3a55476ae2da5d4e5bce8a81b341c675750)

[Kobzol]

Fixes CI failure.

@bors r=jieyouxu

[bors]

📌 Commit 4360c52 has been approved by jieyouxu

It is now in the queue for this repository.

[bors]

⌛ Testing commit 4360c52 with merge 1553adf...

[bors]

☀️ Test successful - checks-actions
Approved by: jieyouxu
Pushing 1553adf to master...

[github-actions]

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 8e62bfd (parent) -> 1553adf (this PR)

Test differences

Show 4 test diffs

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

Test dashboard

Run

cargo run --manifest-path src/ci/citool/Cargo.toml -- \
    test-dashboard 1553adfe6884a8f6c28f5a673d3e605535ee0113 --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-x86_64-apple: 12716.7s -> 7941.2s (-37.6%)
2. x86_64-apple-2: 5341.4s -> 6264.9s (17.3%)
3. aarch64-apple: 5000.5s -> 5830.3s (16.6%)
4. x86_64-gnu-llvm-19-2: 6275.1s -> 7190.7s (14.6%)
5. x86_64-apple-1: 10604.1s -> 9291.6s (-12.4%)
6. dist-aarch64-msvc: 5250.7s -> 5847.6s (11.4%)
7. dist-i586-gnu-i586-i686-musl: 6213.9s -> 5522.7s (-11.1%)
8. dist-aarch64-linux: 6238.5s -> 5632.9s (-9.7%)
9. aarch64-msvc-2: 4761.0s -> 5199.9s (9.2%)
10. arm-android: 6159.5s -> 6648.4s (7.9%)

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.

[rust-timer]

Finished benchmarking commit (1553adf): comparison URL.

Overall result: ❌✅ regressions and improvements - no action needed

@rustbot label: -perf-regression

Instruction count

Our most reliable metric. Used to determine the overall result above. However, even this metric can be noisy.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	0.1%	[0.0%, 0.1%]	2
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-0.3%	[-0.5%, -0.1%]	2
All ❌✅ (primary)	-	-	0

Max RSS (memory usage)

Results (primary 3.6%, secondary -3.8%)

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

	mean	range	count
Regressions ❌ (primary)	3.6%	[3.6%, 3.6%]	1
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-3.8%	[-5.2%, -1.5%]	4
All ❌✅ (primary)	3.6%	[3.6%, 3.6%]	1

Cycles

Results (secondary -1.1%)

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)	6.0%	[6.0%, 6.0%]	1
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-3.5%	[-4.1%, -2.9%]	3
All ❌✅ (primary)	-	-	0

Binary size

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

Bootstrap: 465.671s -> 464.093s (-0.34%)
Artifact size: 377.43 MiB -> 377.76 MiB (0.09%)