Regression: Closure::fromCallable([$this, private]) — Class 'this' not found (re-#23688, Zend/zend_closures.c) #27137

Category

Regression · php-src-strict · Closure · pillar 4

Problem

Closure::fromCallable([$this, 'priv']) for a private instance method must return an invokable Closure (Zend). VM/JIT emit Closure::fromCallable(): Class 'this' not found and never build the closure.

#23688 (2026-07-27) recorded this form as already green on VM. Re-verified 2026-08-03 at 1e28f10a8 — regressed.

FCC ->secret(...) on the same private method still works — only the fromCallable object-array form is broken.

php-src reference

• php/php-src Zend/zend_closures.c — zend_create_closure / object+method callable
• php/php-src Zend/zend_API.c — private method scope checks for callables
• Prior: Regression: Closure::fromCallable([self::class, private]) throws Error not TypeError (zend_closures.c) #23688 (documented working), Regression: Closure::fromCallable([Class, private]) TypeError — Zend creates invokable Closure (re-#23688, Zend/zend_closures.c) #23771, Regression: AOT Closure::fromCallable builds but produces empty output (Zend/zend_closures.c) #26788 (AOT empty output)

PHP implementation target

• lib/VM/ClosureSupport.php (or equivalent fromCallable path) — resolve object operand of [$obj, 'method']; do not stringify to class name this
• PHP-in-PHP; no new runtime/*.c

Repro

./script/docker-exec.sh -- bash -lc 'php bin/vm.php test/repro/maintainer_gap_fromcallable_private.php'
./script/docker-exec.sh -- bash -lc 'php test/repro/maintainer_gap_fromcallable_private.php'

Expect Zend: this_form=7. VM today stops on Class 'this' not found.

Also covered by first half of test/repro/maintainer_gap_fromcallable_static_private_typeerror.php.

Done when

• [, privateMethod] returns invokable Closure on VM (and JIT when LLVM available); invoke matches Zend
• Compliance/repro guard; no silent wrong output
• php-src-strict; no php-compiler-strict shortcut