From: George Koehler Date: 2011-09-28T06:44:09+09:00 Subject: [ruby-core:39752] [Ruby 1.9 - Bug #5376][Open] OpenBSD pthread_np.h present but cannot be compiled Issue #5376 has been reported by George Koehler. ---------------------------------------- Bug #5376: OpenBSD pthread_np.h present but cannot be compiled http://redmine.ruby-lang.org/issues/5376 Author: George Koehler Status: Open Priority: Normal Assignee: Category: Target version: ruby -v: ruby 1.9.4dev (2011-09-28 trunk 33351) [x86_64-openbsd4.9] I run OpenBSD and use autoconf-2.64 to create the configure script. OpenBSD has pthread_np.h, but configure rejects it. From config.log: configure:16017: WARNING: pthread_np.h: present but cannot be compiled configure:16017: WARNING: pthread_np.h: check for missing prerequisite headers? configure:16017: WARNING: pthread_np.h: see the Autoconf documentation configure:16017: WARNING: pthread_np.h: section "Present But Cannot Be Compiled" configure:16017: WARNING: pthread_np.h: proceeding with the compiler's result I called the script as ../configure --prefix=/home/kernigh/prefix --with-baseruby=/usr/local/bin/ruby19 CPPFLAGS=-I/usr/local/include LDFLAGS=-L/usr/local/lib With OpenBSD, requires to #include first. Ruby already does so, but the configure check never does so. The fix is to change the configure check to #include before #include . Use attached patch. -- http://redmine.ruby-lang.org