引用自:http://stackoverflow.com/a/23021454/2544762
Whenever facing an issue of missing a specific file apt-file comes to rescue:
$ apt-file search libXi.so.6
libxi6: /usr/lib/x86_64-linux-gnu/libXi.so.6
libxi6: /usr/lib/x86_64-linux-gnu/libXi.so.6.1.0
libxi6-dbg: /usr/lib/debug/usr/lib/x86_64-linux-gnu/libXi.so.6.1.0
This can be installed via apt-get:
sudo apt-get install apt-file && apt-file update # install and fill the index