[teamleaderleo]

Base red: WindowCleanupCoverageTests.everySuiteThatOpensAWindowClosesWhatItLeaves fails in the tip Swift suite (run 41435160513, job 125243545517):

Expectation failed: (offenders → ["CmuxNextSettingsTests/DisplayBackdropBindingTests.swift:7: DisplayBackdropBindingTests"]).isEmpty → false

Cause: #27092 (per-display wallpaper rotation) added DisplayBackdropBindingTests, which makes NSWindows without .closesItsWindows and never closes them.

Fix (test-only, same pattern as #32086):

• Each test makes its window as a local and closes it with closeAfterTest() in its own teardown, declared before the binding's defer so the binding stops first.
• The suite takes .closesItsWindows and imports CmuxNextTestSupport.
• CmuxNextSettingsTests links CmuxNextTestSupport (Package.swift).

Base-red-job: cmux-next / cmux-next swift test

Changelog

none

Observed / Not run

• Ran scripts/cmux-next/prepush-gate.py: no new violations.
• Not run: the suite itself; this PR's own cmux-next swift test is the evidence.

Agent session: agent session

🤖 Generated with Claude Code

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Summary by cubic

Fixes the Swift suite base red where DisplayBackdropBindingTests leaked NSWindows, failing WindowCleanupCoverageTests.

• Test-only change: each test closes its windows with closeAfterTest(), declared before the binding's defer so the binding stops first.
• The suite now takes .closesItsWindows, and CmuxNextSettingsTests links CmuxNextTestSupport to provide it.

^{Written for commit 27d655c. Summary will update on new commits.}

[github-actions]

cmux status _{(one comment, edited in place; each line is updated by the job that owns it)}

Review 27d655c: HQ feed card · gallery before/after runs · checks

App of this head (app.zip, kept 1 day)

gh workflow run reload-build.yml -R manaflow-ai/cmux --ref feat-cmux-next -f tag=pr32217 -f ref=lane/swift-red-display-backdrop-windows -f platform=macos -f backend_mode=local

Shipped in:

• cmux NEXT nightly 1.0.0-nightly.4144668469201 (91cf7c0aa8)
• cmux NEXT nightly 1.0.0-nightly.4144754641401 (f2a2b6d444)
• cmux NEXT nightly 1.0.0-nightly.4144882653901 (612c99d3c9)
• cmux NEXT nightly 1.0.0-nightly.4144971038501 (5f937c4fc4)
• cmux NEXT nightly 1.0.0-nightly.4145066734501 (6fdfe98ecd)
• cmux NEXT nightly 1.0.0-nightly.4145248477801 (7bfeec05fd)
• cmux NEXT nightly 1.0.0-nightly.4145363708701 (c81ea581fe)

[teamleaderleo]

Review (claude-opus-5-5): SHIP at 27d655c

Review (subagent claude-opus-5-5): SHIP at 27d655c

Checked: all 10 NSWindow() in DisplayBackdropBindingTests.swift get a closeAfterTest() defer, each declared before the binding's stop() defer so stop runs first; no shadowed window names; the suite carries .closesItsWindows on its top-level type, which is what the WindowCleanupCoverageTests scanner looks for; CmuxNextTestSupport is already linked by another daemonSwiftSettings test target and exports closeAfterTest and the trait as public. DisplayBackdropBinding keeps no reference to the window (it is only the notification object), so the release check in pendingFolderReadDoesNotRetainBinding and the temporary binding in the last test mean the same as before.

Follow-ups: none