# Extconf.rb won't build makefile **URL:** \ **Category:** Ruby-Gnome 2\ **Created:** [July 5, 2007, 9:31pm UTC](https://www.ruby-forum.com/t/extconf-rb-wont-build-makefile/108667 "2007-07-05T21:31:13Z")\ **Posts on this page:** 2\ **Page:** 1
**Author:** ![Lindsay\_Morris](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/l/b19c9b/32.png) [@Lindsay\_Morris](https://www.ruby-forum.com/u/Lindsay_Morris)\ **Post date:** [July 5, 2007, 9:31pm UTC](https://www.ruby-forum.com/t/extconf-rb-wont-build-makefile/108667/1 "2007-07-05T21:31:13Z")
My mkmf.log says: * * * conftest.c: In function `t': conftest.c:3: error:`rb\_define\_alloc\_func’ undeclared (first use in this function) conftest.c:3: error: (Each undeclared identifier is reported only once conftest.c:3: error: for each function it appears in.) * * * I am using ruby 1.8.6 on Linux. Gnome is installed. I run “ruby extconf.rb” as root, and get the above. I guess this is a newbie question, but I’ve spent the last hour or two searching google and various forums, and coming up empty. Any crumbs of advice appreciated! – Lindsay ---
**Author:** ![Lindsay\_Morris](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/l/b19c9b/32.png) [@Lindsay\_Morris](https://www.ruby-forum.com/u/Lindsay_Morris)\ **Post date:** [July 5, 2007, 9:34pm UTC](https://www.ruby-forum.com/t/extconf-rb-wont-build-makefile/108667/2 "2007-07-05T21:34:22Z")
Ooops, guess I should at least show the command line it ran: “gcc -o conftest -I. -I/usr/lib/ruby/1.8/i686-linux -I. -I/usr/kerberos/include -I/usr/lib/ruby/site\_ruby/1.8/i686-linux -O2 -march=i686 -g -fPIC -Wall conftest.c -L’/usr/lib’ -Wl,-R’/usr/lib’ -g -L/usr/kerberos/lib -rdynamic -Wl,-export-dynamic -lruby-static -ldl -lcrypt -lm -lc” conftest.c: In function `t': conftest.c:3: error:`rb\_define\_alloc\_func’ undeclared (first use in this function) conftest.c:3: error: (Each undeclared identifier is reported only once conftest.c:3: error: for each function it appears in.)