This is the last release in 2.2.x series. Look forward to PHPStan 2.3.0 which is going to be released next week with the following highlights:

• Massive leap in performance (again!)
• Generics improvements (bidirectional type narrowing which closes [#6732] and dozens of duplicate issues)
• Unused variables detection

Here's what new and changed in PHPStan 2.2.17:

Improvements 🔧

• Compile PHP 8.6 turbo binaries against 8.6.0RC2 (#6599)
• Build Linux ZTS turbo binaries for PHP 8.6+ (#6657)
• Point method visibility errors at the method, not its first attribute (#6630), [#14398], thanks @Cayan!

Bugfixes 🐛

• Cache parsed ASTs behind the path routing, one cache per parser (#6569), [#15231], thanks @SanderMuller!
• Keep optional groups optional within a matched regex alternation branch (#6596), [#15297]
• Do not track string keys of an unpacked non-literal expression in DuplicateKeysInLiteralArraysRule (#6635), [#15295], thanks @VincentLanglet and @staabm!

Performance 🏎️

• Cache a class's ancestors without the class itself (#6593), thanks @SanderMuller!

Function signature fixes 🤖

• Fix the return type of SessionHandler::read() to string|false (#6639), thanks @Firehed!

Internals 🔍

• Load dead-code-detector in self-analysis only on PHP 8.2 and later (#6591), thanks @SanderMuller!
• Mutation testing: diff against a configured branch, cover only the changed files (#6664)