Ruby native extension error on SmartOS when `gem install ffi`

gem_make.out

/usr/local/bin/ruby extconf.rb
checking for ffi.h... *** extconf.rb failed ***
Could not create Makefile due to some reason, probably lack of necessary
libraries and/or headers.  Check the mkmf.log file for more details.  You may
need configuration options.

Provided configuration options:
        --with-opt-dir
        --without-opt-dir
        --with-opt-include
        --without-opt-include=${opt-dir}/include
        --with-opt-lib
        --without-opt-lib=${opt-dir}/lib
        --with-make-prog
        --without-make-prog
        --srcdir=.
        --curdir
        --ruby=/usr/local/bin/ruby
        --with-ffi_c-dir
        --without-ffi_c-dir
        --with-ffi_c-include
        --without-ffi_c-include=${ffi_c-dir}/include
        --with-ffi_c-lib
        --without-ffi_c-lib=${ffi_c-dir}/
        --with-libffi-config
        --without-libffi-config
        --with-pkg-config
        --without-pkg-config
/usr/local/lib/ruby/2.0.0/mkmf.rb:434:in `try_do': The compiler failed to generate an executable file. (RuntimeError)
You have to install development tools first.
        from /usr/local/lib/ruby/2.0.0/mkmf.rb:565:in `try_cpp'
        from /usr/local/lib/ruby/2.0.0/mkmf.rb:1044:in `block in have_header'
        from /usr/local/lib/ruby/2.0.0/mkmf.rb:895:in `block in checking_for'
        from /usr/local/lib/ruby/2.0.0/mkmf.rb:340:in `block (2 levels) in postpone'
        from /usr/local/lib/ruby/2.0.0/mkmf.rb:310:in `open'
        from /usr/local/lib/ruby/2.0.0/mkmf.rb:340:in `block in postpone'
        from /usr/local/lib/ruby/2.0.0/mkmf.rb:310:in `open'
        from /usr/local/lib/ruby/2.0.0/mkmf.rb:336:in `postpone'
        from /usr/local/lib/ruby/2.0.0/mkmf.rb:894:in `checking_for'
        from /usr/local/lib/ruby/2.0.0/mkmf.rb:1043:in `have_header'
        from extconf.rb:16:in `<main>'

mkmf.log

package configuration for libffi is not found
"gcc -o conftest -I/usr/local/include/ruby-2.0.0/x86_64-solaris2.11 -I/usr/local/include/ruby-2.0.0/ruby/backward -I/usr/local/include/ruby-2.0.0 -I.     -O3 -fno-fast-math -ggdb3 -Wall -Wextra -Wno-unused-parameter -Wno-parentheses -Wno-long-long -Wno-missing-field-initializers -Wunused-variable -Wpointer-arith -Wwrite-strings -Wdeclaration-after-statement -Wimplicit-function-declaration -std=c99 conftest.c  -L. -L/usr/local/lib -Wl,-R/usr/local/lib -L. -fstack-protector     -Wl,-R -Wl,/usr/local/lib -L/usr/local/lib -lruby-static  -lpthread -lrt -lsocket -ldl -lcrypt -lm   -lc"
In file included from /usr/local/include/ruby-2.0.0/ruby/ruby.h:1567:0,
                 from /usr/local/include/ruby-2.0.0/ruby.h:33,
                 from conftest.c:1:
/usr/local/include/ruby-2.0.0/ruby/missing.h:212:17: error: expected identifier or '(' before '__extension__'
/usr/local/include/ruby-2.0.0/ruby/missing.h:212:17: error: expected identifier or '(' before ')' token
checked program was:
/* begin */
1: #include "ruby.h"
2:
3: int main(int argc, char **argv)
4: {
5:   return 0;
6: }
/* end */

Did you ever get this sorted ?