Installing any gems in ruby will bring ERROR: failed to build gem native extension

Question

I am using windows 8.1 with Ruby 1.9.3 - when I try to install any gems this error shows:

    ERROR: Failed to build gem native extension.

C:/Ruby193/bin/ruby.exe -r ./siteconf20141011-6892-1pldhkg.rb extconf.rb

checking for ffi.h... no

checking for ffi.h in /usr/local/include,/usr/include/ffi... no

checking for rb_thread_blocking_region()... yes

checking for rb_thread_call_with_gvl()... yes

checking for rb_thread_call_without_gvl()... yes

checking for ffi_prep_cif_var()... no

creating extconf.h

creating Makefile

make clean Makefile:165: *** target pattern contains no `%'. Stop.

make Makefile:165: *** target pattern contains no `%'. Stop.

make failed, exit code 2

Gem files will remain installed in C:/Ruby193/lib/ruby/gems/1.9.1/gems/ffi-1.9.6 for inspection. Results logged to C:/Ruby193/lib/ruby/gems/1.9.1/extensions/x86-mingw32/1.9.1/ff i-1.9.6/gem_make.out

possible duplicate of Cannot install JSON gem in rails using windows — antlersoft
the answer from that question suggests that I install DevKit - I forgot to mention that I already had it installed when the problem occured — user1967281

meroin meroin · Accepted Answer · 2015-02-23T19:58:11

I fixed this problem by reinstalling Ruby (1.9.3) and making sure to check the "Add Ruby executables to your PATH" checkbox during installation.

Source: the first section of this page https://github.com/oneclick/rubyinstaller/wiki/Troubleshooting

Installing any gems in ruby will bring ERROR: failed to build gem native extension

1 Answers