随笔记录：
升级Xcode9后在进行ipa包导出时一直提示The data couldn’t be read because it isn’t in the correct format的错误提示，折腾了好久才算解决了，感觉跟个人的开发环境配置有关系，估计以前某一次升级ruby的时候导致环境异常，低版本的Xcode没有验证，最新的Xcode9做了验证。虽然问题是解决了，但对问题的根源并没有特别理解，零散记一下能记住的解决过程。
导出包时提示The data couldn’t be read because it isn’t in the correct format，对话框的左下角“show logs”查看错误日志发现以下错误：
/System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/fileutils.rb:245:in `mkdir': Permission denied - /Library/Ruby/Gems/2.0.0/extensions/universal-darwin-16/2.0.0/xcodeproj-0.17.0 (Errno::EACCES)
在这里根据网上的方式去尝试执行gem update --system，结果收到以下错误：
ERROR:While executing gem ... (Gem::RemoteFetcher::FetchError)
SSL_connect returned=1 errno=0 state=SSLv2/v3 read server hello A: sslv3 alert handshake failure (https://gems-ruby-china.b0.aicdn.com/specs.4.8.gz)
参照 https://apple.stackexchange.com/questions/83885/ruby-2-0-0-install-via-rvm-errors-surrounding-openssl 网上的方式进行尝试：
$ rvm remove 2.0.0 # get rid of unsuccessful installation
$ rvm get head --autolibs=3 # get the latest RVM and build required libs
$ rvm requirements # just in case, install all other required stuff
$ rvm install ruby-2.0.0
$ rvm --default use ruby-2.0.0
结果在执行 rvm install ruby-2.3.4 时下载超级慢，最后提示错误 ：
There was an error(56).
Failed download
There has been an error fetching the ruby interpreter. Halting the installation.
重新设置了gem源：
$ gem sources -a https://gems.ruby-china.org/
Error fetching https://gems.ruby-china.org/:
SSL_connect returned=1 errno=0 state=SSLv2/v3 read server hello A: sslv3 alert handshake failure (https://gems-ruby-china.b0.aicdn.com/specs.4.8.gz)
$ echo "ruby_url=https://cache.ruby-china.org/pub/ruby" > ~/.rvm/user/db
接着开始尝试安装高版本的ruby：
$ rvm install 2.3.0 --disable-binary
安装过程中报错找不到libyaml-0.2.dylib：
/usr/local/Cellar/ruby/2.4.2/lib/ruby/2.4.0/yaml.rb:5:in `':
It seems your ruby installation is missing psych (for YAML output).
To eliminate this warning, please install libyaml and reinstall your ruby.
/usr/local/Cellar/ruby/2.4.2/lib/ruby/2.4.0/rubygems/core_ext/kernel_require.rb:55:in `require': dlopen(/usr/local/Cellar/ruby/2.4.2/lib/ruby/2.4.0/x86_64-darwin16/psych.bundle, 9): Library not loaded: /usr/local/opt/libyaml/lib/libyaml-0.2.dylib (LoadError)
接下来尝试过重新安装openssl、重新安装ruby、重新安装psych、重新安装libyaml：
$ brew remove openssl
$ brew install openssl
$ rm -rf /usr/local/lib/ruby/site_ruby/
$ brew uninstall ruby
$ brew install ruby
$ gem install psych
$ gem install libyaml
$ rvm pkg install libyaml
$ rvm reinstall all --force
# 重新装yaml
$ cd.rvm/src
$ sudo rm-rf yaml*
$ rvm pkg install libyaml
# 手动下载libyaml
$ tar zxf yaml-0.1.4.tar.gz
$ cd yaml-0.1.4
$ ./configure
$ make
$ make install
最后还是报错，而且错误的路径一直是2.0.0 的版本，最后尝试了把默认2.0.0版本删除了，重新设置默认的ruby版本为2.3.4并update，最终解决了问题：
https://github.com/caskroom/homebrew-cask/issues/7732
$ rm -rf /Library/Ruby/Gems/2.0.0
$ gem update --system
现在依然是一知半解的状态，怀疑应该是当初升级ruby后某个环境变量指错了，在进行ipa导出的时候两个版本的ruby都被用到了。附带一些参考的链接：
https://stackoverflow.com/questions/15738883/please-install-libyaml-and-reinstall-your-ruby
https://stackoverflow.com/questions/10392495/installing-libyaml-for-ruby-on-a-mac-osx-lion
https://github.com/caskroom/homebrew-cask/issues/7732
http://www.cocoachina.com/ios/20141018/9958.html
https://stackoverflow.com/questions/12092468/install-libtools-on-mac
https://github.com/Homebrew/homebrew-core/issues/11636
https://github.com/Homebrew/homebrew-core/issues/11635
有人来答疑解惑一下最好了！！！
