[GianniCarlo]

The 6.0.0 release check couldn't get an upgrade result: the previous release (5.22.2) crashed at launch on both iOS 26.5 and 27.0 before seeding its data.

Cause

retarget() makes a copy of the candidate's .xctestrun that installs the previous release's app, but it kept the candidate's UITargetAppEnvironmentVariables. Those carry DYLD_FRAMEWORK_PATH / DYLD_LIBRARY_PATH pointing at the candidate's build products, so the old app loaded the candidate's BookPlayerKit.framework instead of the one it embeds. The crash reports say so:

Termination: DYLD, Symbol missing
Symbol not found: _$s13BookPlayerKit10TimeParserC14getTimerOption4fromAA0gH0OSgSd_tFZ
Referenced from: …/BookPlayer.app/BookPlayer            (5.22.2)
Expected in:     /private/tmp/*/BookPlayerKit.framework/BookPlayerKit   (the candidate's build)

#1653 removed TimeParser.getTimerOption(from:), so 5.22.2 couldn't start. The cached 5.22.2 app embeds its own BookPlayerKit with that symbol, so App Store users upgrading from 5.22.2 aren't affected; only the check was. The script then fell back to building 5.22.1, which ran the Mac out of disk. Before #1653, the candidate's framework happened to be a superset, so earlier upgrade checks ran the old app on the new framework without anyone noticing.

Fix

The copy drops every DYLD_* key from UITargetAppEnvironmentVariables, so the previous release runs on the frameworks it ships with. The test runner's own environment (TestingEnvironmentVariables) is untouched. CLAUDE.md's release-check paragraph says so.

Testing

A full run of the check from this branch (develop e7ecc8f + this fix), Xcode 27.1, previous release 5.22.2 from the cache, passed in 14.9 min:

iOS	fresh	import	playback	upgrade from 5.22.2
26.5	✅	✅	✅	✅
27.0	✅	✅	✅	✅

The same build without the fix: upgrade crashed on both (the missing symbol above), then the 5.22.1 fallback build ran out of disk.

[github-actions]

✅ Claude PR Review — PASS

Changes only the release-check script and CLAUDE.md. retarget() builds the copy of the candidate's .xctestrun that installs the previous release. It now removes every DYLD_* key from UITargetAppEnvironmentVariables, so the old app loads the BookPlayerKit it embeds instead of the candidate's build. That fixes the 5.22.2 launch crash (missing symbol) after #1653. retarget()'s only caller is previous_xctestrun, so the candidate's own .xctestrun still points at its build products. TestingEnvironmentVariables isn't touched. The keys are collected before deleting, and a missing key falls back to an empty dict, so neither case breaks. No app, BookPlayerKit, concurrency, player/AVAudioSession, CoreData/SwiftData or auth/entitlement code is affected. The CLAUDE.md note is accurate.

Findings: no findings

Converged: nothing new this round, and no earlier finding is open.

_{Model claude-opus-5-5 · run log · 0 new · 0 carried over · 0 resolved · advisory (a human should still review). Findings are de-duplicated across pushes; an earlier finding closes only when the verification pass judges it against the current code — fixed, no longer applicable, accepted by a maintainer, or a duplicate of a finding reported on this push.}