Thanks to visit codestin.com
Credit goes to github.com

Skip to content

[ty] Fix panic for cyclic star imports #21428

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom
Merged
MichaReiser merged 3 commits into from
Nov 13, 2025
Merged

[ty] Fix panic for cyclic star imports #21428

MichaReiser merged 3 commits into from
Nov 13, 2025

Conversation

@MichaReiser
Copy link
Member

@MichaReiser MichaReiser commented Nov 13, 2025 •
edited
Loading

Summary

Fixes astral-sh/ty#444

This PR fixes a panic where the export_names query never converged for a cyclic star import.

This is a rather silly bug. The cycle never converged because the symbol ordering changed between iterations (forever)....

Here's a diff between the exported symbols before the fix for the last two iterations

https://www.diffchecker.com/tk3ihAdo/

This PR fixes the bug by simply sorting the names before returning.

I considered using a BTreeMap but found the sort slightly simpler (and both roughly have the same complexity)

Test Plan

I recreated the MRE from the linked issue and verified that it panics without my changes.

@MichaReiser MichaReiser added bug Something isn't working ty Multi-file analysis & type inference labels Nov 13, 2025
@astral-sh-bot
Copy link

astral-sh-bot bot commented Nov 13, 2025 •
edited
Loading

Diagnostic diff on typing conformance tests

No changes detected when running ty on typing conformance tests ✅

@astral-sh-bot
Copy link

astral-sh-bot bot commented Nov 13, 2025 •
edited
Loading

mypy_primer results

Changes were detected when running on open source projects 
scikit-build-core (https://github.com/scikit-build/scikit-build-core)
+ src/scikit_build_core/build/wheel.py:98:20: error[no-matching-overload] No overload of bound method `__init__` matches arguments
- Found 44 diagnostics
+ Found 45 diagnostics

No memory usage changes detected ✅

@AlexWaygood
Copy link
Member

AlexWaygood commented Nov 13, 2025

Oh, wow, and the iteration order matters because the query itself returns Box<[Name]> rather than returning the FxHashMap directly (because if it returned the FxHashMap directly, two maps with the same entries would still compare equal even if they were differently ordered)... what a bug.....

AlexWaygood
AlexWaygood approved these changes Nov 13, 2025
View reviewed changes
Copy link
Member

@AlexWaygood AlexWaygood left a comment

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

brilliant

@MichaReiser
Copy link
Member Author

MichaReiser commented Nov 13, 2025 •
edited
Loading

Come on Github... start those CI jobs. I want to see the perf impact.

@MichaReiser MichaReiser force-pushed the micha/fix-exported-names-too-many-iterations branch from d905851 to 14294a1 Compare November 13, 2025 14:18
@MichaReiser MichaReiser merged commit 67e54ff into main Nov 13, 2025
41 checks passed
@MichaReiser MichaReiser deleted the micha/fix-exported-names-too-many-iterations branch November 13, 2025 14:38
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment

Reviewers

@AlexWaygood AlexWaygood AlexWaygood approved these changes

@carljm carljm Awaiting requested review from carljm carljm is a code owner

@sharkdp sharkdp Awaiting requested review from sharkdp sharkdp is a code owner

@dcreager dcreager Awaiting requested review from dcreager dcreager is a code owner

Assignees

No one assigned

Labels

bug Something isn't working ty Multi-file analysis & type inference

Projects

None yet

Milestone

No milestone

Development

Successfully merging this pull request may close these issues.

[panic] Panic 'too many cycle iterations' for recursive star import

3 participants

@MichaReiser @AlexWaygood