Podspec Lint错误

Question

我尝试创建一个podspec文件，其中一个文件需要使用--fno-objc-arc标志进行编译。我一直将我的podspec文件基于this，我的podspec文件如下：

Pod::Spec.new do |s|
    s.name     = "PPToolBox"
    s.version  = "0.0.1"
    s.summary  = "Convenient helper methods."
    s.homepage = "https://bitbucket.org/wasappli/homepage"


    # ―――  Spec License  ――――――――――――――――――――――――――――――――――――――――――――――――――――――――――― #
    #
    #  Licensing your code is important. See http://choosealicense.com for more info.
    #  CocoaPods will detect a license file if there is a named LICENSE*
    #  Popular ones are 'MIT', 'BSD' and 'Apache License, Version 2.0'.
    #

    # s.license      = "MIT (example)"
    # s.license      = { :type => "MIT", :file => "FILE_LICENSE" }
    # ------------------------------------------------------------------------------ #

    s.author   = "Wasappli"
    s.platform = :ios, "6.0"

    s.source = {
        :git    => 'https://mdewolfe@bitbucket.org/mdewolfe/myrepo.git',
        :commit => '974f6d9'
    }

    s.source_files = 'source/*.{h,m}'
    s.framework    = "SystemConfiguration"
    s.requires_arc = true

    non_arc_files    = 'source/GTMNSString+HTML.m'
    s.exclude_files = non_arc_files

    s.subspec 'pptoolbox-no-arc' do |sp|
        sp.source_files   =  non_arc_files
        sp.requires_arc   = false
    end
end

最终结果是仅将排除文件添加到Lint/Pods项目中。如何创建将无弧标志添加到给定文件（或文件集）的子规范？