fix --dry-run when the change-id warning is printed

[jyn514]

previously:

Building bootstrap
   Compiling bootstrap v0.0.0 (/home/jyn/src/rust2/src/bootstrap)
    Finished dev [unoptimized] target(s) in 4.23s
thread 'main' panicked at src/bin/main.rs:147:17:
fs::write(warned_id_path, latest_change_id.to_string()) failed with No such file or directory (os error 2)

[rustbot]

r? @Mark-Simulacrum

(rustbot has picked a reviewer for you, use r? to override)

[rustbot]

This PR modifies src/bootstrap/src/core/config.

If appropriate, please update CONFIG_CHANGE_HISTORY in src/bootstrap/src/utils/change_tracker.rs and change-id in config.example.toml.

[onur-ozkan]

@bors r+ rollup

[bors]

📌 Commit 520662e has been approved by onur-ozkan

It is now in the queue for this repository.

[bors]

⌛ Testing commit 520662e with merge 529047c...

[bors]

☀️ Test successful - checks-actions
Approved by: onur-ozkan
Pushing 529047c to master...

[rust-timer]

Finished benchmarking commit (529047c): comparison URL.

Overall result: ❌ regressions - ACTION NEEDED

Next Steps: If you can justify the regressions found in this perf run, please indicate this with @rustbot label: +perf-regression-triaged along with sufficient written justification. If you cannot justify the regressions please open an issue or create a new PR that fixes the regressions, add a comment linking to the newly created issue or PR, and then add the perf-regression-triaged label to this PR.

@rustbot label: +perf-regression
cc @rust-lang/wg-compiler-performance

Instruction count

This is a highly reliable metric that was used to determine the overall result at the top of this comment.

	mean	range	count
Regressions ❌ (primary)	0.9%	[0.8%, 1.0%]	4
Regressions ❌ (secondary)	0.5%	[0.3%, 0.8%]	18
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	0.9%	[0.8%, 1.0%]	4

Max RSS (memory usage)

Results

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)	0.6%	[0.5%, 0.6%]	4
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-0.5%	[-0.5%, -0.5%]	1
Improvements ✅ (secondary)	-3.8%	[-3.8%, -3.8%]	1
All ❌✅ (primary)	0.3%	[-0.5%, 0.6%]	5

Cycles

Results

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)	0.8%	[0.8%, 0.8%]	1
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-1.3%	[-1.3%, -1.3%]	1
Improvements ✅ (secondary)	-2.1%	[-2.1%, -2.1%]	1
All ❌✅ (primary)	-0.2%	[-1.3%, 0.8%]	2

Binary size

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

Bootstrap: 671.102s -> 672.087s (0.15%)
Artifact size: 312.48 MiB -> 312.43 MiB (-0.02%)

[lqd]

I think the noise threshold on these benchmarks was somehow lower recently, and is now picking back up to its regular level, hence regressions within a range that is usually ignored. Obviously this bootstrap PR has no impact on compiler performance whatsoever.

@rustbot label: +perf-regression-triaged