Issue #15072 has been updated by normalperson (Eric Wong). Status changed from Open to Closed Fixed in #15130 ---------------------------------------- Bug #15072: thread.c:4356:5: error: implicit declaration of function ‘ubf_list_atfork’ https://bugs.ruby-lang.org/issues/15072#change-100886 * Author: duerst (Martin Dürst) * Status: Closed * Priority: Normal * Assignee: normalperson (Eric Wong) * ruby -v: ruby 2.6.0dev (2018-08-01 trunk 64156) [x86_64-cygwin] * Backport: 2.3: UNKNOWN, 2.4: UNKNOWN, 2.5: UNKNOWN ---------------------------------------- When compiling on cygwin, I get the following error: ``` compiling thread.c thread.c: In function ‘rb_thread_atfork_internal’: thread.c:4356:5: error: implicit declaration of function ‘ubf_list_atfork’ [-Werror=implicit-function-declaration] ubf_list_atfork(); ^~~~~~~~~~~~~~~ ``` The `ubf_list_atfork` function was introduced by issue #15013 in r64485. The problem is that the function is defined *as static* in thread_pthread.c, but is used in thread.c. Not being an expert on threads, I thought that maybe `ubf_list_atfork` is a function that's available on some OSes, but that can't be the case. I only got empty results when searching for it. There's also a macro for `ubf_list_atfork` in thread_win32.c, but that doesn't seem to be related here. [below it says my Ruby version is trunk 64156, but I'm compiling on HEAD.] -- https://bugs.ruby-lang.org/