Revert "Add expansion info to implied bounds" by JonathanBrouwer · Pull Request #158122 · rust-lang/rust

JonathanBrouwer · 2026-06-19T08:51:14Z

This reverts PR #157702 because it causes an ICE and a significant perf regression. This PR also adds a regression test for the ICE.

r? ghost
cc @oli-obk @estebank @davidtwco

Fixes #158093

…pansion-info, r=davidtwco,estebank" This reverts commit 18509d2, reversing changes made to bf0dfb6.

rustbot · 2026-06-19T08:51:18Z

HIR ty lowering was modified

cc @fmease

rustbot · 2026-06-19T08:51:20Z

⚠️ Warning ⚠️

There are issue links (such as #123) in the commit messages of the following commits.
Please move them to the PR description, to avoid spamming the issues with references to the commit, and so this bot can automatically canonicalize them to avoid issues with subtree.
- 0676d2e

JonathanBrouwer · 2026-06-19T08:52:12Z

@bors try @rust-timer queue

Revert "Add expansion info to implied bounds"

rust-bors · 2026-06-19T11:01:54Z

☀️ Try build successful (CI)
Build commit: 7e32970 (7e3297093340be87843a6cfe127723386872d136)
Base parent: 8e15021 (8e150217bafcaaaa0c45bf685c55fd56cec48598)

rust-timer · 2026-06-19T11:42:02Z

Finished benchmarking commit (7e32970): comparison URL.

Overall result: ✅ improvements - no action needed

Benchmarking means the PR may be perf-sensitive. It's automatically marked not fit for rolling up. Overriding is possible but disadvised: it risks changing compiler perf.

@bors rollup=never
@rustbot label: -S-waiting-on-perf -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)	1.1%	[0.8%, 1.4%]	2
Improvements ✅ (primary)	-0.6%	[-2.8%, -0.1%]	76
Improvements ✅ (secondary)	-0.6%	[-1.8%, -0.2%]	56
All ❌✅ (primary)	-0.6%	[-2.8%, -0.1%]	76

Max RSS (memory usage)

Results (primary -1.9%, secondary -2.3%)

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

	mean	range	count
Regressions ❌ (primary)	1.0%	[1.0%, 1.0%]	1
Regressions ❌ (secondary)	5.0%	[2.5%, 6.1%]	4
Improvements ✅ (primary)	-2.1%	[-4.2%, -0.6%]	24
Improvements ✅ (secondary)	-5.2%	[-12.7%, -0.9%]	10
All ❌✅ (primary)	-1.9%	[-4.2%, 1.0%]	25

Cycles

Results (primary -3.0%, secondary -2.4%)

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)	2.5%	[2.2%, 2.7%]	3
Improvements ✅ (primary)	-3.0%	[-4.4%, -2.0%]	16
Improvements ✅ (secondary)	-3.3%	[-5.1%, -2.3%]	17
All ❌✅ (primary)	-3.0%	[-4.4%, -2.0%]	16

Binary size

Results (primary -1.7%, secondary -1.7%)

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)	-	-	0
Improvements ✅ (primary)	-1.7%	[-11.0%, -0.0%]	110
Improvements ✅ (secondary)	-1.7%	[-10.7%, -0.0%]	66
All ❌✅ (primary)	-1.7%	[-11.0%, -0.0%]	110

Bootstrap: 481.812s -> 480.604s (-0.25%)
Artifact size: 390.71 MiB -> 391.19 MiB (0.12%)

JonathanBrouwer · 2026-06-19T11:47:08Z

r? compiler

JonathanBrouwer · 2026-06-19T12:03:26Z

If you have r+ privileges, you can self-approve a revert if the revert is clean and is unlikely to cause new regressions on its own

The revert was clean and I think unlikely to cause regressions
@bors r+ rollup=never

rust-bors · 2026-06-19T12:03:30Z

📌 Commit 1e5f587 has been approved by JonathanBrouwer

It is now in the queue for this repository.

🌲 The tree is currently closed for pull requests below priority 5. This pull request will be tested once the tree is reopened.

JonathanBrouwer · 2026-06-19T12:28:37Z

@bors p=5
Scheduling this to run after the rollup

@oli-obk

…thanBrouwer Revert "Add expansion info to implied bounds" This reverts PR #157702 because it causes an ICE and a significant perf regression. This PR also adds a regression test for the ICE. r? ghost cc @oli-obk @estebank @davidtwco Fixes #158093

rust-log-analyzer · 2026-06-19T15:05:57Z

The job x86_64-gnu-tools failed! Check out the build log: (web) (plain enhanced) (plain)

Click to see the possible cause of the failure (guessed by this bot)

...............................F.................. (50/144)
.................................................. (100/144)
............................................       (144/144)

======== tests/rustdoc-gui/go-to-collapsed-elem.goml ========

[ERROR] line 40
    at `tests/rustdoc-gui/go-to-collapsed-elem.goml` line 21: Error: Node is detached from document: for command `click: "//*[@id='search']//a[@href='../test_docs/struct.Foo.html#method.must_use']"`
    at <file:///checkout/obj/build/x86_64-unknown-linux-gnu/test/rustdoc-gui/doc/test_docs/struct.Foo.html?search=t_use>


<= doc-ui tests done: 143 succeeded, 1 failed, 0 filtered out

Error: ()

rust-bors · 2026-06-19T15:06:24Z

💔 Test for 272d4be failed: CI. Failed job:

auto - x86_64-gnu-tools (web logs, enhanced plaintext logs)

JonathanBrouwer · 2026-06-19T15:07:02Z

@bors retry

rust-bors · 2026-06-19T18:14:05Z

☀️ Test successful - CI
Approved by: JonathanBrouwer
Duration: 3h 6m 6s
Pushing d806608 to main...

github-actions · 2026-06-19T18:16:56Z

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 0c1748c (parent) -> d806608 (this PR)

Test differences

Show 2 test diffs

Stage 1

[incremental] tests/incremental/explicit_supertraits_containing_assoc_item.rs: [missing] -> pass (J1)

Stage 2

[incremental] tests/incremental/explicit_supertraits_containing_assoc_item.rs: [missing] -> pass (J0)

Job group index

Test dashboard

Run

cargo run --manifest-path src/ci/citool/Cargo.toml -- \
    test-dashboard d80660864fab37b060d052e01fd3ec40e4d33d11 --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

dist-i686-linux: 1h 4m -> 1h 50m (+72.0%)
dist-i686-msvc: 1h 23m -> 2h 17m (+65.3%)
x86_64-gnu-gcc-core-tests: 13m 22s -> 8m 20s (-37.6%)
dist-x86_64-musl: 1h 43m -> 2h 9m (+25.3%)
x86_64-msvc-ext2: 1h 42m -> 1h 22m (-20.0%)
dist-x86_64-mingw: 2h 34m -> 2h 4m (-19.2%)
aarch64-apple-macos-26: 3h 14m -> 2h 37m (-19.1%)
dist-android: 27m 30s -> 23m 4s (-16.1%)
aarch64-apple: 3h 19m -> 2h 47m (-15.8%)
x86_64-gnu-gcc: 1h 9m -> 59m 20s (-14.6%)

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.

oli-obk · 2026-06-19T18:25:57Z

Thanks! I should have checked whether that's a perf regression, seems obvious in hindsight

rust-timer · 2026-06-19T18:55:32Z

Finished benchmarking commit (d806608): comparison URL.

Overall result: ✅ 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)	0.2%	[0.2%, 0.2%]	1
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-0.6%	[-2.9%, -0.1%]	76
Improvements ✅ (secondary)	-0.6%	[-1.8%, -0.2%]	57
All ❌✅ (primary)	-0.6%	[-2.9%, 0.2%]	77

Max RSS (memory usage)

Results (primary -2.0%, secondary -2.0%)

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)	5.3%	[2.6%, 6.3%]	4
Improvements ✅ (primary)	-2.0%	[-4.7%, -0.6%]	28
Improvements ✅ (secondary)	-4.6%	[-12.2%, -0.8%]	11
All ❌✅ (primary)	-2.0%	[-4.7%, -0.6%]	28

Cycles

Results (primary -3.5%, secondary -1.8%)

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)	2.8%	[1.7%, 4.4%]	3
Improvements ✅ (primary)	-3.5%	[-4.7%, -2.1%]	10
Improvements ✅ (secondary)	-2.9%	[-3.6%, -2.2%]	13
All ❌✅ (primary)	-3.5%	[-4.7%, -2.1%]	10

Binary size

Results (primary -1.5%, secondary -1.6%)

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

	mean	range	count
Regressions ❌ (primary)	0.1%	[0.1%, 0.1%]	20
Regressions ❌ (secondary)	0.1%	[0.0%, 0.1%]	16
Improvements ✅ (primary)	-1.9%	[-11.0%, -0.0%]	97
Improvements ✅ (secondary)	-2.1%	[-10.7%, -0.0%]	52
All ❌✅ (primary)	-1.5%	[-11.0%, 0.1%]	117

Bootstrap: 480.627s -> 481.965s (0.28%)
Artifact size: 391.14 MiB -> 390.67 MiB (-0.12%)

Revert "Rollup merge of rust-lang#157702 - oli-obk:having-fun-with-ex…

0676d2e

…pansion-info, r=davidtwco,estebank" This reverts commit 18509d2, reversing changes made to bf0dfb6.

rustbot added S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. T-compiler Relevant to the compiler team, which will review and decide on the PR/issue. labels Jun 19, 2026

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rust-bors Bot pushed a commit that referenced this pull request Jun 19, 2026

Auto merge of #158122 - JonathanBrouwer:revert-expansion-info, r=<try>

7e32970

Revert "Add expansion info to implied bounds"

JonathanBrouwer mentioned this pull request Jun 19, 2026

Add expansion info to implied bounds #157702

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Add regression test for ICE

1e5f587

rustbot removed the S-waiting-on-perf Status: Waiting on a perf run to be completed. label Jun 19, 2026

rustbot assigned chenyukang Jun 19, 2026

rust-bors Bot 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 Jun 19, 2026

JonathanBrouwer assigned JonathanBrouwer and unassigned chenyukang Jun 19, 2026

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rust-bors Bot added S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. and removed S-waiting-on-bors Status: Waiting on bors to run and complete tests. Bors will change the label on completion. labels Jun 19, 2026

rust-bors Bot 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 Jun 19, 2026

rust-bors Bot mentioned this pull request Jun 19, 2026

Rollup of 4 pull requests #158135

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This was referenced Jun 19, 2026

ICE: Found unstable fingerprints for explicit_supertraits_containing_assoc_item on incremental rebuild when any #[derive] is added #158131

Closed

[ICE]: encountered incremental compilation error with explicit_supertraits_containing_assoc_item #158133

Closed

rust-bors Bot added merged-by-bors This PR was explicitly merged by bors. and removed S-waiting-on-bors Status: Waiting on bors to run and complete tests. Bors will change the label on completion. labels Jun 19, 2026

rust-bors Bot merged commit d806608 into rust-lang:main Jun 19, 2026
14 checks passed

rustbot added this to the 1.98.0 milestone Jun 19, 2026

rust-bors Bot mentioned this pull request Jun 19, 2026

Implement param bounds on non-lifetime binders #158031

Draft

panayang mentioned this pull request Jun 20, 2026

ICE: unstable fingerprints for explicit_supertraits_containing_assoc_item (MetaSized supertrait) from uninhabited_references under incremental + --fix rust-lang/rust-clippy#17262

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Overall result: ✅ improvements - no action needed

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Test differences

Stage 1

Stage 2

Job duration changes

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Overall result: ✅ improvements - no action needed

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