socket (and many others) not building on osx?

I'm stumped. A brand new clean build doesn't build socket.

% cd /tmp
% uname -a
Darwin wrath-zenspider-com.local 8.7.1 Darwin Kernel Version 8.7.1:  
Wed Jun  7 16:19:56 PDT 2006; root:xnu-792.9.72.obj~2/RELEASE_I386  
i386 i386
% gcc_select
Current default compiler:
gcc version 4.0.1 (Apple Computer, Inc. build 5341)
% (cvs -d [e-mail]:/src co -r ruby_1_8 ruby; cd  
ruby; autoconf && ./configure && make -j 4 && make check) &> /tmp/ 
ruby.log
% tail -20 /tmp/ruby.log
/usr/bin/ld: warning multiple definitions of symbol _setreuid
./libruby-static.a(process.o) definition of _setreuid in section  
(__TEXT,__text)
/usr/lib/gcc/i686-apple-darwin8/4.0.1/../../../libdl.dylib 
(setreuid.So) definition of _setreuid
test succeeded
./miniruby  ./runruby.rb --extout=.ext -- -C "./test" runner.rb -- 
runner=console
/private/tmp/ruby/lib/ipaddr.rb:13:in `require': no such file to load  
-- socket (LoadError)
         from /private/tmp/ruby/lib/ipaddr.rb:13
         from /private/tmp/ruby/lib/drb/acl.rb:8:in `require'
         from /private/tmp/ruby/lib/drb/acl.rb:8
         from ./drb/test_acl.rb:8:in `require'
         from ./drb/test_acl.rb:8
         from /private/tmp/ruby/lib/test/unit/collector/dir.rb:83:in  
`require'
         from /private/tmp/ruby/lib/test/unit/collector/dir.rb:83:in  
`collect_file'
         from /private/tmp/ruby/lib/test/unit/collector/dir.rb:66:in  
`recursive_collect'
          ... 7 levels...
         from /private/tmp/ruby/lib/test/unit/autorunner.rb:198:in `[]'
         from /private/tmp/ruby/lib/test/unit/autorunner.rb:198:in `run'
         from /private/tmp/ruby/lib/test/unit/autorunner.rb:13:in `run'
         from runner.rb:7
make: *** [test-all] Error 1

Looks like nothing is probing for socket.h:

15 matches for "socket" in buffer: ruby.log
     422:cvs checkout: Updating ruby/ext/socket
     423:U ruby/ext/socket/.cvsignore
     424:U ruby/ext/socket/addrinfo.h
     425:U ruby/ext/socket/depend
     426:U ruby/ext/socket/extconf.rb
     427:U ruby/ext/socket/getaddrinfo.c
     428:U ruby/ext/socket/getnameinfo.c
     429:U ruby/ext/socket/socket.c
     430:U ruby/ext/socket/sockport.h
    2586:cvs checkout: Updating ruby/test/socket
    2587:U ruby/test/socket/test_nonblock.rb
    2588:U ruby/test/socket/test_socket.rb
    2589:U ruby/test/socket/test_unix.rb
    3279:compiling socket
(which shows no build at all)
    3313:/private/tmp/ruby/lib/ipaddr.rb:13:in `require': no such  
file to load -- socket (LoadError)

http://www.rafb.net/paste/results/c81pJG19.txt for the full log