Using built-in specs.
COLLECT_GCC=i686-w64-mingw32-gcc
COLLECT_LTO_WRAPPER=/usr/lib/gcc/i686-w64-mingw32/4.9.2/lto-wrapper
Target: i686-w64-mingw32
Configured with: /build/mingw-w64-gcc/src/gcc-4.9.2/configure --prefix=/usr --libexecdir=/usr/lib --target=i686-w64-mingw32 --enable-languages=c,lto,c++,objc,obj-c++,fortran,ada --enable-shared --enable-static --enable-threads=posix --enable-fully-dynamic-string --enable-libstdcxx-time=yes --with-system-zlib --enable-cloog-backend=isl --enable-lto --disable-dw2-exceptions --enable-libgomp --disable-multilib --enable-checking=release --disable-libssp
Thread model: posix
gcc version 4.9.2 (GCC) 
ext/extinit.o: In function `Init_ext':
ext/extinit.c:12: undefined reference to `Init_bigdecimal'
ext/extinit.c:13: undefined reference to `Init_continuation'
ext/extinit.c:14: undefined reference to `Init_coverage'
ext/extinit.c:15: undefined reference to `Init_date_core'
ext/extinit.c:16: undefined reference to `Init_dbm'
ext/extinit.c:17: undefined reference to `Init_digest'
ext/extinit.c:18: undefined reference to `Init_bubblebabble'
ext/extinit.c:19: undefined reference to `Init_md5'
ext/extinit.c:20: undefined reference to `Init_rmd160'
ext/extinit.c:21: undefined reference to `Init_sha1'
ext/extinit.c:22: undefined reference to `Init_sha2'
ext/extinit.c:23: undefined reference to `Init_etc'
ext/extinit.c:24: undefined reference to `Init_fcntl'
ext/extinit.c:25: undefined reference to `Init_fiber'
ext/extinit.c:26: undefined reference to `Init_gdbm'
ext/extinit.c:27: undefined reference to `Init_console'
ext/extinit.c:28: undefined reference to `Init_nonblock'
ext/extinit.c:29: undefined reference to `Init_wait'
ext/extinit.c:30: undefined reference to `Init_generator'
ext/extinit.c:31: undefined reference to `Init_parser'
ext/extinit.c:32: undefined reference to `Init_complex'
ext/extinit.c:33: undefined reference to `Init_rational'
ext/extinit.c:34: undefined reference to `Init_nkf'
ext/extinit.c:35: undefined reference to `Init_objspace'
ext/extinit.c:36: undefined reference to `Init_openssl'
ext/extinit.c:37: undefined reference to `Init_pathname'
ext/extinit.c:38: undefined reference to `Init_psych'
ext/extinit.c:39: undefined reference to `Init_cparse'
ext/extinit.c:40: undefined reference to `Init_sizeof'
ext/extinit.c:41: undefined reference to `Init_ripper'
ext/extinit.c:42: undefined reference to `Init_socket'
ext/extinit.c:43: undefined reference to `Init_stringio'
ext/extinit.c:44: undefined reference to `Init_strscan'
ext/extinit.c:45: undefined reference to `Init_thread'
ext/extinit.c:46: undefined reference to `Init_tcltklib'
ext/extinit.c:47: undefined reference to `Init_tkutil'
ext/extinit.c:48: undefined reference to `Init_win32ole'
ext/extinit.c:49: undefined reference to `Init_zlib'
collect2: error: ld returned 1 exit status
make[2]: *** [ruby.exe] Error 1
make[2]: *** Waiting for unfinished jobs....
ext/extinit.o: In function `Init_ext':
ext/extinit.c:12: undefined reference to `Init_bigdecimal'
ext/extinit.c:13: undefined reference to `Init_continuation'
ext/extinit.c:14: undefined reference to `Init_coverage'
ext/extinit.c:15: undefined reference to `Init_date_core'
ext/extinit.c:16: undefined reference to `Init_dbm'
ext/extinit.c:17: undefined reference to `Init_digest'
ext/extinit.c:18: undefined reference to `Init_bubblebabble'
ext/extinit.c:19: undefined reference to `Init_md5'
ext/extinit.c:20: undefined reference to `Init_rmd160'
ext/extinit.c:21: undefined reference to `Init_sha1'
ext/extinit.c:22: undefined reference to `Init_sha2'
ext/extinit.c:23: undefined reference to `Init_etc'
ext/extinit.c:24: undefined reference to `Init_fcntl'
ext/extinit.c:25: undefined reference to `Init_fiber'
ext/extinit.c:26: undefined reference to `Init_gdbm'
ext/extinit.c:27: undefined reference to `Init_console'
ext/extinit.c:28: undefined reference to `Init_nonblock'
ext/extinit.c:29: undefined reference to `Init_wait'
ext/extinit.c:30: undefined reference to `Init_generator'
ext/extinit.c:31: undefined reference to `Init_parser'
ext/extinit.c:32: undefined reference to `Init_complex'
ext/extinit.c:33: undefined reference to `Init_rational'
ext/extinit.c:34: undefined reference to `Init_nkf'
ext/extinit.c:35: undefined reference to `Init_objspace'
ext/extinit.c:36: undefined reference to `Init_openssl'
ext/extinit.c:37: undefined reference to `Init_pathname'
ext/extinit.c:38: undefined reference to `Init_psych'
ext/extinit.c:39: undefined reference to `Init_cparse'
ext/extinit.c:40: undefined reference to `Init_sizeof'
ext/extinit.c:41: undefined reference to `Init_ripper'
ext/extinit.c:42: undefined reference to `Init_socket'
ext/extinit.c:43: undefined reference to `Init_stringio'
ext/extinit.c:44: undefined reference to `Init_strscan'
ext/extinit.c:45: undefined reference to `Init_thread'
ext/extinit.c:46: undefined reference to `Init_tcltklib'
ext/extinit.c:47: undefined reference to `Init_tkutil'
ext/extinit.c:48: undefined reference to `Init_win32ole'
ext/extinit.c:49: undefined reference to `Init_zlib'
collect2: error: ld returned 1 exit status
make[2]: *** [rubyw.exe] Error 1
make[1]: *** [static] Error 2
make: *** [build-ext] Error 2