search_for

# File lib/rubygems/resolver.rb, line 225
  def search_for(dependency)
    possibles, all = find_possible(dependency)
    if !@soft_missing && possibles.empty?
      @missing << dependency
      exc = Gem::UnsatisfiableDependencyError.new dependency, all
      exc.errors = @set.errors
      raise exc
    end
    possibles.sort_by { |s| [s.source, s.version, Gem::Platform.local =~ s.platform ? 1 : 0] }.
      map { |s| ActivationRequest.new s, dependency, [] }
  end