Issue #21817 has been updated by nobu (Nobuyoshi Nakada). Tags set to box Status changed from Open to Assigned Assignee set to tagomoris (Satoshi Tagomori) Backport changed from 3.2: UNKNOWN, 3.3: UNKNOWN, 3.4: UNKNOWN, 4.0: UNKNOWN to 3.2: DONTNEED, 3.3: DONTNEED, 3.4: DONTNEED, 4.0: REQUIRED ---------------------------------------- Bug #21817: Ruby::Box crashes with refinement + bind_call + Symbol#to_proc combination https://bugs.ruby-lang.org/issues/21817#change-115932 * Author: ahogappa (sho hirano) * Status: Assigned * Assignee: tagomoris (Satoshi Tagomori) * ruby -v: ruby 4.0.0 (2025-12-25 revision 553f1675f3) +PRISM [arm64-darwin25] * Backport: 3.2: DONTNEED, 3.3: DONTNEED, 3.4: DONTNEED, 4.0: REQUIRED ---------------------------------------- ## Description When running with `RUBY_BOX=1`, a combination of refinement on Binding class, `bind_call`, and `Symbol#to_proc` causes a crash with the error: `[BUG] BUG: Local ep without cme/box, flags: 66660087` ## Reproduction Script ```ruby # Run with: RUBY_BOX=1 ruby repro.rb using Module.new { refine ::Binding do def eval_methods ::Kernel.instance_method(:methods).bind_call(receiver) end end } p binding.eval_methods.map(&:to_s) ``` ## Expected Behavior The script should return an array of method names as strings. ## Actual Behavior Ruby crashes with `[BUG] BUG: Local ep without cme/box, flags: 66660087` ## Workaround Using block form instead of Symbol#to_proc does not crash: ```ruby binding.eval_methods.map { it.to_s } # This works ``` ---Files-------------------------------- ruby-2026-01-02-063109.ips (10.2 KB) -- https://bugs.ruby-lang.org/