Received this error when trying to push to Heroku. My node.js app depends on slug 0.2.2 > unicode 0.3.1 > bufferstream 0.5.1 > buffertools 1.0.3

heroku push error

> unicode@0.4.3 postinstall /tmp/build_26v36bla740ep/node_modules/slug/node_modules/unicode
> ./install.js

module.js:485
  process.dlopen(filename, module.exports);
         ^
Error: /tmp/build_26v36bla740ep/node_modules/slug/node_modules/unicode/node_modules/bufferstream/node_modules/buffertools/build/Release/buffertools.node: invalid ELF header
    at Object.Module._extensions..node (module.js:485:11)
    at Module.load (module.js:356:32)
    at Function.Module._load (module.js:312:12)
    at Module.require (module.js:362:17)
    at require (module.js:378:17)
    at Object.<anonymous> (/tmp/build_26v36bla740ep/node_modules/slug/node_modules/unicode/node_modules/bufferstream/node_modules/buffertools/buffertools.js:1:77)
    at Module._compile (module.js:449:26)
    at Object.Module._extensions..js (module.js:467:10)
    at Module.load (module.js:356:32)
    at Function.Module._load (module.js:312:12)
npm ERR! unicode@0.4.3 postinstall: `./install.js`
npm ERR! `sh "-c" "./install.js"` failed with 1
npm ERR! 
npm ERR! Failed at the unicode@0.4.3 postinstall script.
npm ERR! This is most likely a problem with the unicode package,
npm ERR! not with npm itself.
npm ERR! Tell the author that this fails on your system:
npm ERR!     ./install.js
npm ERR! You can get their info via:
npm ERR!     npm owner ls unicode
npm ERR! There is likely additional logging output above.

npm ERR! System Linux 2.6.32-350-ec2
npm ERR! command "/tmp/node-node-BEvo/bin/node" "/tmp/node-npm-sh9D/cli.js" "rebuild"
npm ERR! cwd /tmp/build_26v36bla740ep
npm ERR! node -v v0.8.14
npm ERR! npm -v 1.1.65
npm ERR! code ELIFECYCLE
npm ERR! 
npm ERR! Additional logging details can be found in:
npm ERR!     /tmp/build_26v36bla740ep/npm-debug.log
npm ERR! not ok code 0
Failed to rebuild dependencies with npm
Heroku push rejected, failed to compile Node.js app