用Doxygen生成文档时，在处理一个图片时报如下错误：

sh: dot: not found
Problems running dot: exit code=127, command='dot', arguments='"/home/liheyuan/code/zookeeper-3.3.3/src/c/docs/html/zookeeper_8h__incl.dot" -Tpng -o "/home/liheyuan/code/zookeeper-3.3.3/src/c/docs/html/zookeeper_8h__incl.png"'
sh: dot: not found

如下解决：

sudo apt-get install graphviz