When trying to compile a project, I started to receive the error fatal error: xxhash.h: No such file or directory. I tried to install liblz4-dev, but that didn’t seem to fix the error (looking at the repo, it looks as though xxhash was removed in revision 123).
Eventually, I decided to just download the relevant files and place them in /usr/include which fixed the issue,
cd /usr/include
sudo wget http://lz4.googlecode.com/svn-history/r122/trunk/programs/xxhash.c
sudo wget http://lz4.googlecode.com/svn-history/r122/trunk/programs/xxhash.h
Then, when I tried to compile the project it worked fine