Issue #22327 has been reported by znz (Kazuhiro NISHIYAMA). ---------------------------------------- Bug #22327: RubyVM::ZJIT.reset_stats! aborts the process (Rust panic) when ZJIT is not enabled https://bugs.ruby-lang.org/issues/22327 * Author: znz (Kazuhiro NISHIYAMA) * Status: Open * Assignee: jit * ruby -v: ruby 4.0.7 (2026-09-15 revision 229531a6cf) +PRISM [x86_64-linux] * Backport: 3.3: DONTNEED, 3.4: DONTNEED, 4.0: REQUIRED ---------------------------------------- `RubyVM::ZJIT.reset_stats!` aborts the whole process with a Rust panic when it is called while ZJIT is not enabled. The other stats methods (`stats`, `stats_string`, `stats_enabled?`) just return `nil`/`false` in the same situation, and `RubyVM::YJIT.reset_stats!` returns `nil` when YJIT is disabled, so I think `reset_stats!` should also be a no-op instead of crashing. ## Reproduction ``` $ ruby -e 'p RubyVM::ZJIT.enabled?; RubyVM::ZJIT.reset_stats!; puts "after"' false thread '<unnamed>' (1) panicked at /usr/src/ruby/zjit/src/state.rs:200:13: ZJITState::get_instance called when ZJIT is not enabled note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace thread '<unnamed>' (1) panicked at .../library/core/src/panicking.rs:225:5: panic in a function that cannot unwind (backtrace and bug report dump follow) Aborted (core dumped) $ echo $? 134 ``` Expected: `after` is printed and the process exits with 0 (`reset_stats!` returns `nil`, as it does when ZJIT is enabled). Reproduced with: - ruby 4.1.0dev (2026-09-15T06:59:41Z master 0c3c61ca82) +PRISM [x86_64-linux] (`ghcr.io/ruby/ruby:master`; panic at `zjit/src/state.rs:200`) - ruby 4.0.7 (2026-09-15 revision 229531a6cf) +PRISM [x86_64-linux] (`ghcr.io/ruby/ruby:4.0.7`; panic at `zjit/src/state.rs:168`) For comparison, these do not crash: ``` $ ruby -e 'p RubyVM::ZJIT.stats, RubyVM::ZJIT.stats_string, RubyVM::ZJIT.stats_enabled?' nil nil false $ ruby -e 'p RubyVM::YJIT.enabled?, RubyVM::YJIT.reset_stats!' false nil $ ruby --zjit -e 'p RubyVM::ZJIT.enabled?, RubyVM::ZJIT.reset_stats!' true nil ``` ## Cause `rb_zjit_reset_stats_bang` in `zjit/src/stats.rs` calls `ZJITState::get_counters()` etc. unconditionally, and `ZJITState::get_instance` panics when the state has not been initialized. `rb_zjit_stats` in the same file starts with `if !zjit_enabled_p() { return Qnil; }`; adding the same guard to `rb_zjit_reset_stats_bang` would fix this. 🤖 Generated with [Claude Code](https://claude.com/claude-code) -- https://bugs.ruby-lang.org/