rb_async_bug_errno  286 process.c      #define execv(path, argv) (rb_async_bug_errno("unreachable: async-signal-unsafe execv() is called", 0))
rb_async_bug_errno  298 process.c              rb_async_bug_errno("BUG timer thread still running", 0 /* EDOOFUS */);
rb_async_bug_errno 1280 thread_pthread.c     rb_async_bug_errno(buff, errno_arg);
rb_async_bug_errno 1474 thread_pthread.c 	    rb_async_bug_errno("thread_timer: select", e);