问题：
我有我正在研究的这颗宝石。尝试在本地安装它以进行一些测试时，rake install构建 gem 后失败。Rake 建议我运行gem install构建的 gem 来调试。令人惊讶的是，gem install pkg/my_gem-x.y.z.gem它就像一个魅力！
知道为什么吗？
一些细节：
耙版本：10.0.3
使用 bundler 版本创建的 Gem：1.2.1
gemspec的内容：
lib = File.expand_path('../lib', __FILE__)
$LOAD_PATH.unshift(lib) unless $LOAD_PATH.include?(lib)
require 'my_gem/version'
Gem::Specification.new do |gem|
gem.name = "mygem"
gem.version = MyGem::VERSION
gem.authors = ["Omar Abdel-Wahab"]
gem.email = ["me@example.com"]
gem.description = %q{bla bla bla}
gem.summary = %q{bla bla bla}
gem.homepage = "http://github.com/foobar/"
gem.files = `git ls-files`.split($/)
gem.executables = gem.files.grep(%r{^bin/}).map{ |f| File.basename(f) }
gem.test_files = gem.files.grep(%r{^(test|spec|features)/})
gem.require_paths = ["lib"]
gem.add_dependency "rails", ">= 3.1"
gem.add_dependency "jquery-rails"
gem.add_dependency "twitter-bootstrap-rails", ">= 2.1.0"
gem.add_development_dependency "bundler", ">= 1.0.0"
gem.add_development_dependency "rspec", "~> 2.3"
gem.add_development_dependency "sqlite3-ruby"
end
输出rake install：
~/Projects/Github/my_gem% rake -vt install
** Invoke install (first_time)
** Execute install
my_gem 0.0.1 built to pkg/my_gem-0.0.1.gem
rake aborted!
Couldn't install gem, run `gem install /Users/owahab/Projects/Github/my_gem/pkg/my_gem-0.0.1.gem' for more detailed output
/Users/owahab/.rvm/gems/ruby-1.9.3-p286/gems/bundler-1.2.1/lib/bundler/gem_helper.rb:68:in `install_gem'
/Users/owahab/.rvm/gems/ruby-1.9.3-p286/gems/bundler-1.2.1/lib/bundler/gem_helper.rb:43:in `block in install'
/Users/owahab/.rvm/gems/ruby-1.9.3-p286/gems/rake-10.0.3/lib/rake/task.rb:228:in `call'
/Users/owahab/.rvm/gems/ruby-1.9.3-p286/gems/rake-10.0.3/lib/rake/task.rb:228:in `block in execute'
/Users/owahab/.rvm/gems/ruby-1.9.3-p286/gems/rake-10.0.3/lib/rake/task.rb:223:in `each'
/Users/owahab/.rvm/gems/ruby-1.9.3-p286/gems/rake-10.0.3/lib/rake/task.rb:223:in `execute'
/Users/owahab/.rvm/gems/ruby-1.9.3-p286/gems/rake-10.0.3/lib/rake/task.rb:166:in `block in invoke_with_call_chain'
/Users/owahab/.rvm/rubies/ruby-1.9.3-p286/lib/ruby/1.9.1/monitor.rb:211:in `mon_synchronize'
/Users/owahab/.rvm/gems/ruby-1.9.3-p286/gems/rake-10.0.3/lib/rake/task.rb:159:in `invoke_with_call_chain'
/Users/owahab/.rvm/gems/ruby-1.9.3-p286/gems/rake-10.0.3/lib/rake/task.rb:152:in `invoke'
/Users/owahab/.rvm/gems/ruby-1.9.3-p286/gems/rake-10.0.3/lib/rake/application.rb:143:in `invoke_task'
/Users/owahab/.rvm/gems/ruby-1.9.3-p286/gems/rake-10.0.3/lib/rake/application.rb:101:in `block (2 levels) in top_level'
/Users/owahab/.rvm/gems/ruby-1.9.3-p286/gems/rake-10.0.3/lib/rake/application.rb:101:in `each'
/Users/owahab/.rvm/gems/ruby-1.9.3-p286/gems/rake-10.0.3/lib/rake/application.rb:101:in `block in top_level'
/Users/owahab/.rvm/gems/ruby-1.9.3-p286/gems/rake-10.0.3/lib/rake/application.rb:110:in `run_with_threads'
/Users/owahab/.rvm/gems/ruby-1.9.3-p286/gems/rake-10.0.3/lib/rake/application.rb:95:in `top_level'
/Users/owahab/.rvm/gems/ruby-1.9.3-p286/gems/rake-10.0.3/lib/rake/application.rb:73:in `block in run'
/Users/owahab/.rvm/gems/ruby-1.9.3-p286/gems/rake-10.0.3/lib/rake/application.rb:160:in `standard_exception_handling'
/Users/owahab/.rvm/gems/ruby-1.9.3-p286/gems/rake-10.0.3/lib/rake/application.rb:70:in `run'
/Users/owahab/.rvm/gems/ruby-1.9.3-p286/gems/rake-10.0.3/bin/rake:33:in `<top (required)>'
/Users/owahab/.rvm/gems/ruby-1.9.3-p286/bin/rake:19:in `load'
/Users/owahab/.rvm/gems/ruby-1.9.3-p286/bin/rake:19:in `<main>'
/Users/owahab/.rvm/gems/ruby-1.9.3-p286/bin/ruby_noexec_wrapper:14:in `eval'
/Users/owahab/.rvm/gems/ruby-1.9.3-p286/bin/ruby_noexec_wrapper:14:in `<main>'
Tasks: TOP => install
rake build从那时起的输出gem install：
~/Projects/Github/rails_autocomplete% rake build && gem install pkg/my_gem-0.0.1.gem
my_gem 0.0.1 built to pkg/my_gem-0.0.1.gem
Successfully installed my_gem-0.0.1
1 gem installed
Installing ri documentation for my_gem-0.0.1...
Building YARD (yri) index for my_gem-0.0.1...
Installing RDoc documentation for my_gem-0.0.1...