C:\Users\This\Desktop\gltail-master\bin>gem install ruby-opengl
Fetching: ruby-opengl-0.61.0.gem (100%)
Successfully installed ruby-opengl-0.61.0
Parsing documentation for ruby-opengl-0.61.0
Installing ri documentation for ruby-opengl-0.61.0
1 gem installed

C:\Users\This\Desktop\gltail-master\bin>gem list opengl

*** LOCAL GEMS ***

opengl (0.9.0 ruby x86-mingw32, 0.8.0 x86-mingw32)

C:\Users\This\Desktop\gltail-master\bin>ruby gl_tail gl_tail.yaml
fatal: Not a git repository (or any of the parent directories): .git
c:/ruby200/lib/ruby/gems/2.0.0/gems/opengl-0.8.0-x86-mingw32/lib/opengl.rb:29:in
 `require': 126: The specified module could not be found.   - c:/ruby200/lib/rub
y/gems/2.0.0/gems/opengl-0.8.0-x86-mingw32/lib/opengl/opengl.so (LoadError)
        from c:/ruby200/lib/ruby/gems/2.0.0/gems/opengl-0.8.0-x86-mingw32/lib/op
engl.rb:29:in `<top (required)>'
        from C:/Users/This/Desktop/gltail-master/lib/gl_tail.rb:14:in `require'
        from C:/Users/This/Desktop/gltail-master/lib/gl_tail.rb:14:in `<top (req
uired)>'
        from c:/ruby200/lib/ruby/2.0.0/rubygems/core_ext/kernel_require.rb:55:in
 `require'
        from c:/ruby200/lib/ruby/2.0.0/rubygems/core_ext/kernel_require.rb:55:in
 `require'
        from gl_tail:77:in `<main>'

C:\Users\This\Desktop\gltail-master\bin>