问题

Could not find function xmlCheckVersion in library libxml2

解决办法

Homebrew doesn't link libxml and libxslt to avoid conflicts. You need to --force them.

brew link libxml2 --force
brew link libxslt --force

I faced this problem when I upgraded to latest OS X. I wrote a blog post on it detailing the issue.

参考资料

• http://stackoverflow.com/questions/34240287/trouble-installing-lxml-with-pip