bundle install 找不到库文件，用 config 参数指定本地类库

在 FreeBSD Jail 中安装 Gitlab，执行 bundle install 时，有个类库文件找不到，最后修改 config 文件顺利通过。

出现的错误：

Building nokogiri using packaged libraries.
-----
libiconv is missing.  please visit http://nokogiri.org/tutorials/installing_nokogiri.html for help with installing dependencies.
-----

直接用 gem ，指定类库路径后可以，但 bundle install 不行

gem install nokogiri --   --use-system-libraries   --with-xml2-lib=/usr/local/lib   --with-xml2-include=/usr/local/include/libxml2/libxml   --with-xslt-lib=/usr/local/lib   --with-xslt-include=/usr/local/include/libxslt   --with-iconv-lib=/usr/local/lib   --with-iconv-include=/usr/local/include

修改 ~/.bundle/config 添加这些参数到 BUNDLE_BUILD_NOKOGIRI

cat .bundle/config
---
BUNDLE_BUILD__NOKOGIRI: --use-system-libraries --with-xml2-lib=/usr/local/lib --with-xml2-include=/usr/local/include/libxml2/libxml
  --with-xslt-lib=/usr/local/lib --with-xslt-include=/usr/local/include/libxslt --with-iconv-lib=/usr/local/lib
  --with-iconv-include=/usr/local/include    

重新运行 bunlde install，顺利完成安装。

参考：

https://gist.github.com/afair/ac3cf215ed5bc89cd40c

http://bundler.io/bundle_config.html

http://doc.gitlab.com/ce/install/installation.html

https://www.freebsdnews.com/2015/03/26/gitlab-freebsd-10/

http://www.freshports.org/search.php

http://doc.freenas.org/9.3/freenas_jails.html#installing-freebsd-packages

https://ruby.taobao.org/