我unf_ext 0.7.4在 Ubuntu 上安装时遇到了麻烦。我已经尝试了你可以想象的所有形式的谷歌搜索，并安装了我能想到的几乎所有东西，这是我迄今为止安装的：
- libgmp-dev
- 红宝石开发
- zlib1g-dev
- liblzma-dev
- 构建必备
- 构建必要补丁
- libxml2
- libxslt1.1
- openssl
- libreadline6
- libreadline6-dev
- 卷曲
- 混帐核心
- zlib1g
- zlib1g-dev
- libssl-开发
- libyaml 开发
- libsqlite3-0
- libsqlite3-dev
- sqlite3（在某处找到一个链接说这会有所帮助？）
- libxml2-dev
- libxslt-开发
- 自动配置
- libc6-dev
- ncurses-开发
- 汽车制造
- 库工具
- 野牛
但是在安装完所有这些之后它仍然无法正常工作，所以我尝试了
sudo apt-get update && sudo apt-get install libxml2-dev && sudo apt-get install libxslt-dev && sudo gem install unf_ext
在此期间，我收到此错误：
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:
The following packages have unmet dependencies:
libxml2-dev : Depends: libxml2 (= 2.9.1+dfsg1-3ubuntu4.9) but 2.9.4+dfsg1-2.2 is to be installed
E: Unable to correct problems, you have held broken packages.
但是，dpkg --get-selections没有显示任何软件包，hold并且都已安装。如何成功安装此 gem？