4.0 open Due in 20 days (12/25/2025) 88% 18 issues (16 closed — 2 open) Related issues Feature #19057: Hide implementation of `rb_io_t`. Actions Feature #21221: Proposal to upstream ZJIT Actions Feature #21262: Proposal: `Ractor::Port` Actions Feature #21268: Implement a lock-free hash set for fstring table Actions Feature #21275: Update to Unicode 17.0 Actions Feature #21311: Namespace on read (revised) Actions Feature #21550: Ractor.shareable_proc/shareable_lambda to make sharable Proc object Actions Feature #21557: Ractor.shareable_proc to make sharable Proc objects, safely and flexibly Actions Feature #21701: Enumerator.produce accepts an optional `size` keyword argument Actions