Opencv Ruby Highgui - build gem "manually" -

Opencv Ruby Highgui - build gem "manually" -

i've followed of steps question: highgui , ruby

opencv installed via brew, , rb_webcam installed via gem install.

require "opencv" require "rb_webcam" capture = webcam.new

the error is:

/users/swills/.rvm/rubies/ruby-2.1.1/lib/ruby/gems/2.1.0/gems/nice-ffi-0.4/lib/nice-ffi/library.rb:98:in `load_library': not load highgui. (loaderror) /users/swills/.rvm/rubies/ruby-2.1.1/lib/ruby/gems/2.1.0/gems/rb_webcam-0.3.0/lib/rb_webcam.rb:7:in `<module:highgui>' /users/swills/.rvm/rubies/ruby-2.1.1/lib/ruby/gems/2.1.0/gems/rb_webcam-0.3.0/lib/rb_webcam.rb:4:in `<top (required)>' /users/swills/.rvm/rubies/ruby-2.1.1/lib/ruby/2.1.0/rubygems/core_ext/kernel_require.rb:135:in `require' /users/swills/.rvm/rubies/ruby-2.1.1/lib/ruby/2.1.0/rubygems/core_ext/kernel_require.rb:135:in `rescue in require' /users/swills/.rvm/rubies/ruby-2.1.1/lib/ruby/2.1.0/rubygems/core_ext/kernel_require.rb:144:in `require' gem_testing.rb:3:in `<main>'

in other stackoverflow post above, the user made post said they-

"solved downloading gem here https://github.com/tyounanmoti/rb_webcam , building , installing manually."

my question is, how solve building , installing manually?

(especially if 'gem install rb_webcam' isn't considered manual installation).

ruby opencv highgui