Issue #5433 has been updated by Nobuyoshi Nakada. Status changed from Feedback to Third Party's Issue Obviously, kernel bug. ---------------------------------------- Bug #5433: PTY.spawn Kernel panic on macos lion http://redmine.ruby-lang.org/issues/5433 Author: Gamaliel Toro Status: Third Party's Issue Priority: Normal Assignee: Kenta Murata Category: Target version: ruby -v: ruby-1.9.2 If you execute a PTY.spawn with a non existing command give a kernel panic. Example require 'pty' PTY.spawn('nonexistent-command') -- http://redmine.ruby-lang.org