Earlier versions of pandoc don't have the `default.html5` template file. When `make docs` is run, the build process fails with this message.
pandoc: doc/rust.html
pandoc: /usr/share/pandoc-1.8.2.1/templates/default.html5: openFile: does not exist (No such file or directory)
node.js:201
throw e; // process.nextTick error, or 'error' event on first tick
^
Error: write EPIPE
at errnoException (net.js:670:11)
at Object.afterWrite [as oncomplete] (net.js:503:19)
make: *** [doc/rust.html] Error 1