title: node-qrcode install on heroku
body: <p>I got problem to install this package on heroku.
  Is there a way to do it ?</p>
  
  <p>I saw it's a problem with canvas module, but i don't know what to do.</p>
  
  <p>This is a log of installation on heroku. I don't know how to get more :</p>
  
  <pre><code>npm ERR! canvas@0.12.1 preinstall: `node-waf configure build`
         npm ERR! `sh "-c" "node-waf configure build"` failed with 1
         npm ERR! 
         npm ERR! Failed at the canvas@0.12.1 preinstall script.
         npm ERR! This is most likely a problem with the canvas package,
         npm ERR! not with npm itself.
         npm ERR! Tell the author that this fails on your system:
         npm ERR!     node-waf configure build
         npm ERR! You can get their info via:
         npm ERR!     npm owner ls canvas
         npm ERR! There is likely additional logging output above.
  
         npm ERR! System Linux 2.6.32-343-ec2
         npm ERR! command "/tmp/node-node-La1F/bin/node" "/tmp/node-npm-6Xts/cli.js" "install" "--production"
         npm ERR! cwd /tmp/build_3ejt8evom1p0g
         npm ERR! node -v v0.6.18
         npm ERR! npm -v 1.1.41
         npm ERR! code ELIFECYCLE
         npm ERR! stack Error: canvas@0.12.1 preinstall: `node-waf configure build`
         npm ERR! stack `sh "-c" "node-waf configure build"` failed with 1
         npm ERR! stack     at ChildProcess.&lt;anonymous&gt; (/tmp/node-npm-6Xts/lib/utils/exec.js:56:20)
         npm ERR! stack     at ChildProcess.emit (events.js:70:17)
         npm ERR! stack     at maybeExit (child_process.js:362:16)
         npm ERR! stack     at Process.onexit (child_process.js:398:5)
  </code></pre>