λ ~/ master* npm i -g crossword
/Users/howard/.nvm/versions/node/v5.5.0/bin/crosswordjs -> /Users/howard/.nvm/versions/node/v5.5.0/lib/node_modules/crossword/cli.js
> canvas@1.3.10 install /Users/howard/.nvm/versions/node/v5.5.0/lib/node_modules/crossword/node_modules/canvas
> node-gyp rebuild
Package cairo was not found in the pkg-config search path.
Perhaps you should add the directory containing `cairo.pc'
to the PKG_CONFIG_PATH environment variable
No package 'cairo' found
gyp: Call to './util/has_lib.sh freetype' returned exit status 0. while trying to load binding.gyp
gyp ERR! configure error
gyp ERR! stack Error: `gyp` failed with exit code: 1
gyp ERR! stack at ChildProcess.onCpExit (/Users/howard/.nvm/versions/node/v5.5.0/lib/node_modules/npm/node_modules/node-gyp/lib/configure.js:355:16)
gyp ERR! stack at emitTwo (events.js:100:13)
gyp ERR! stack at ChildProcess.emit (events.js:185:7)
gyp ERR! stack at Process.ChildProcess._handle.onexit (internal/child_process.js:200:12)
gyp ERR! System Darwin 15.3.0
gyp ERR! command "/Users/howard/.nvm/versions/node/v5.5.0/bin/node" "/Users/howard/.nvm/versions/node/v5.5.0/lib/node_modules/npm/node_modules/node-gyp/bin/node-gyp.js" "rebuild"
gyp ERR! cwd /Users/howard/.nvm/versions/node/v5.5.0/lib/node_modules/crossword/node_modules/canvas
gyp ERR! node -v v5.5.0
gyp ERR! node-gyp -v v3.0.3
gyp ERR! not ok
npm WARN install:canvas@1.3.10 canvas@1.3.10 install: `node-gyp rebuild`
npm WARN install:canvas@1.3.10 Exit status 1
Please mention these pre-requirements in the readme: https://github.com/Automattic/node-canvas/wiki/Installation---OSX
brew install pkg-config pixman cairo
Otherwise one will end up with: