jtalavera@jessetg-test:~$ sudo gem2.0 install jekyll
Fetching: posix-spawn-0.3.11.gem (100%)
Building native extensions.  This could take a while...
ERROR:  Error installing jekyll:
        ERROR: Failed to build gem native extension.

    /usr/bin/ruby2.0 extconf.rb
creating Makefile

make "DESTDIR="
compiling posix-spawn.c
In file included from /usr/include/ruby-2.0.0/ruby.h:33:0,
                 from posix-spawn.c:14:
/usr/include/ruby-2.0.0/ruby/ruby.h:121:14: error: size of array ‘ruby_check_sizeof_long’ is negative
 typedef char ruby_check_sizeof_long[SIZEOF_LONG == sizeof(long) ? 1 : -1];
              ^
/usr/include/ruby-2.0.0/ruby/ruby.h:125:14: error: size of array ‘ruby_check_sizeof_voidp’ is negative
 typedef char ruby_check_sizeof_voidp[SIZEOF_VOIDP == sizeof(void*) ? 1 : -1];
              ^
In file included from /usr/include/ruby-2.0.0/ruby.h:33:0,
                 from posix-spawn.c:14:
/usr/include/ruby-2.0.0/ruby/ruby.h: In function ‘rb_float_value’:
/usr/include/ruby-2.0.0/ruby/ruby.h:773:6: warning: right shift count >= width of type [enabled by default]
      VALUE b63 = (v >> 63);
      ^
/usr/include/ruby-2.0.0/ruby/ruby.h: In function ‘rb_float_new’:
/usr/include/ruby-2.0.0/ruby/ruby.h:799:5: warning: right shift count >= width of type [enabled by default]
     bits = (int)((VALUE)(t.v >> 60) & 0x7);
     ^
/usr/include/ruby-2.0.0/ruby/ruby.h:812:6: warning: large integer implicitly truncated to unsigned type [-Woverflow]
      return 0x8000000000000002;
      ^
In file included from /usr/include/ruby-2.0.0/ruby/intern.h:43:0,
                 from /usr/include/ruby-2.0.0/ruby/ruby.h:1568,
                 from /usr/include/ruby-2.0.0/ruby.h:33,
                 from posix-spawn.c:14:
/usr/include/ruby-2.0.0/ruby/st.h: At top level:
/usr/include/ruby-2.0.0/ruby/st.h:67:14: error: size of array ‘st_check_for_sizeof_st_index_t’ is negative
 typedef char st_check_for_sizeof_st_index_t[SIZEOF_VOIDP == (int)sizeof(st_index_t) ? 1 : -1];
              ^
make: *** [posix-spawn.o] Error 1


Gem files will remain installed in /var/lib/gems/2.0.0/gems/posix-spawn-0.3.11 for inspection.
Results logged to /var/lib/gems/2.0.0/gems/posix-spawn-0.3.11/ext/gem_make.out
jtalavera@jessetg-test:~$