我已按照此问题的所有步骤进行操作：Highgui and ruby
opencv是通过brew安装的，rb_webcam是通过gem install安装的。
require "opencv"
require "rb_webcam"
capture = Webcam.new
错误是：
/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': Could not load highgui. (LoadError)
from /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>'
from /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)>'
from /Users/swills/.rvm/rubies/ruby-2.1.1/lib/ruby/2.1.0/rubygems/core_ext/kernel_require.rb:135:in `require'
from /Users/swills/.rvm/rubies/ruby-2.1.1/lib/ruby/2.1.0/rubygems/core_ext/kernel_require.rb:135:in `rescue in require'
from /Users/swills/.rvm/rubies/ruby-2.1.1/lib/ruby/2.1.0/rubygems/core_ext/kernel_require.rb:144:in `require'
from gem_testing.rb:3:in `<main>'
在上面的另一个stackoverflow帖子中，用户发帖说他们 -
＆＃34;通过从此处https://github.com/TyounanMOTI/rb_webcam下载gem并手动构建和安装来解决此问题。＆＃34;
我的问题是，如何通过手动构建和安装来解决它？
（特别是如果＆＃39; gem install rb_webcam＆＃39;不考虑手动安装）。