Make the assertion in Ident::new debug-only.

[nnethercote]

This fixes a perf regression introduced in #140252.

r? @oli-obk

[nnethercote]

@bors try @rust-timer queue

[bors]

⌛ Trying commit 4cb9f03 with merge d4db70f0e2b077f9fd17b3afbed53bea1d1feb2a...

[bors]

☀️ Try build successful - checks-actions
Build commit: d4db70f (d4db70f0e2b077f9fd17b3afbed53bea1d1feb2a)

[rust-timer]

Finished benchmarking commit (d4db70f): comparison URL.

Overall result: ✅ improvements - no action needed

Benchmarking this pull request likely means that it is perf-sensitive, so we're automatically marking it as not fit for rolling up. While you can manually mark this PR as fit for rollup, we strongly recommend not doing so since this PR may lead to changes in compiler perf.

@bors rollup=never
@rustbot label: -S-waiting-on-perf -perf-regression

Instruction count

This is the most reliable metric that we have; it was used to determine the overall result at the top of this comment. However, even this metric can sometimes exhibit noise.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	0.6%	[0.6%, 0.6%]	1
Improvements ✅ (primary)	-0.4%	[-1.1%, -0.1%]	96
Improvements ✅ (secondary)	-0.4%	[-0.5%, -0.2%]	30
All ❌✅ (primary)	-0.4%	[-1.1%, -0.1%]	96

Max RSS (memory usage)

Results (primary 0.1%, secondary -5.0%)

This is a less reliable metric that may be of interest but was not used to determine the overall result at the top of this comment.

	mean	range	count
Regressions ❌ (primary)	0.7%	[0.5%, 0.8%]	4
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-1.1%	[-1.8%, -0.5%]	2
Improvements ✅ (secondary)	-5.0%	[-5.0%, -5.0%]	1
All ❌✅ (primary)	0.1%	[-1.8%, 0.8%]	6

Cycles

Results (primary -0.2%, secondary -5.8%)

This is a less reliable metric that may be of interest but was not used to determine the overall result at the top of this comment.

	mean	range	count
Regressions ❌ (primary)	0.7%	[0.7%, 0.7%]	1
Regressions ❌ (secondary)	2.3%	[2.3%, 2.3%]	1
Improvements ✅ (primary)	-0.5%	[-0.6%, -0.4%]	4
Improvements ✅ (secondary)	-7.4%	[-8.2%, -6.8%]	5
All ❌✅ (primary)	-0.2%	[-0.6%, 0.7%]	5

Binary size

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

Bootstrap: 773.559s -> 773.11s (-0.06%)
Artifact size: 365.71 MiB -> 365.22 MiB (-0.13%)

[nnethercote]

Perf results look good: the regression is undone.

[oli-obk]

@bors r+

[bors]

📌 Commit 4cb9f03 has been approved by oli-obk

It is now in the queue for this repository.

[bors]

⌛ Testing commit 4cb9f03 with merge 7e432c4...

[bors]

☀️ Test successful - checks-actions
Approved by: oli-obk
Pushing 7e432c4 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 bfb44c8 (parent) -> 7e432c4 (this PR)

Test differences

No test diffs found

Test dashboard

Run

cargo run --manifest-path src/ci/citool/Cargo.toml -- \
    test-dashboard 7e432c456bf58ad436f3a92c2a3e3c27f399f14a --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: 6995.0s -> 10065.7s (43.9%)
2. x86_64-apple-1: 6603.4s -> 9124.2s (38.2%)
3. dist-aarch64-linux: 7721.6s -> 5443.2s (-29.5%)
4. dist-apple-various: 5757.7s -> 7452.6s (29.4%)
5. x86_64-apple-2: 4046.1s -> 4795.2s (18.5%)
6. dist-arm-linux: 5507.1s -> 4791.6s (-13.0%)
7. dist-various-1: 4753.6s -> 4330.9s (-8.9%)
8. x86_64-gnu-llvm-19-2: 5920.0s -> 6233.6s (5.3%)
9. dist-android: 2511.1s -> 2634.0s (4.9%)
10. x86_64-gnu-llvm-19-3: 7046.4s -> 6722.1s (-4.6%)

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 (7e432c4): comparison URL.

Overall result: ✅ improvements - no action needed

@rustbot label: -perf-regression

Instruction count

This is the most reliable metric that we have; it was used to determine the overall result at the top of this comment. However, even this metric can sometimes exhibit noise.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-0.3%	[-1.1%, -0.1%]	115
Improvements ✅ (secondary)	-0.4%	[-0.7%, -0.2%]	34
All ❌✅ (primary)	-0.3%	[-1.1%, -0.1%]	115

Max RSS (memory usage)

Results (primary 0.8%, secondary -0.8%)

This is a less reliable metric that may be of interest but was not used to determine the overall result at the top of this comment.

	mean	range	count
Regressions ❌ (primary)	1.5%	[0.4%, 5.1%]	8
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-1.2%	[-2.2%, -0.4%]	3
Improvements ✅ (secondary)	-0.8%	[-0.8%, -0.8%]	1
All ❌✅ (primary)	0.8%	[-2.2%, 5.1%]	11

Cycles

Results (primary -0.1%, secondary -0.1%)

This is a less reliable metric that may be of interest but was not used to determine the overall result at the top of this comment.

	mean	range	count
Regressions ❌ (primary)	0.9%	[0.9%, 0.9%]	1
Regressions ❌ (secondary)	2.3%	[2.3%, 2.3%]	1
Improvements ✅ (primary)	-0.5%	[-0.6%, -0.5%]	2
Improvements ✅ (secondary)	-2.5%	[-2.5%, -2.5%]	1
All ❌✅ (primary)	-0.1%	[-0.6%, 0.9%]	3

Binary size

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

Bootstrap: 772.768s -> 772.638s (-0.02%)
Artifact size: 365.84 MiB -> 365.44 MiB (-0.11%)