Errors Pushing to Heroku (node.js)

Question

When I push a default express app to heroku I get the following error. I've ensured I am up to date with heroku-toolbelt etc but it appears to be an error from the heroku side? Has anyone seen this? It pushes alright and works as expected but I suspect this could cause issues in the future.

Counting objects: 7, done.
Delta compression using up to 4 threads.
Compressing objects: 100% (3/3), done.
Writing objects: 100% (4/4), 404 bytes, done.
Total 4 (delta 1), reused 0 (delta 0)

-----> Heroku receiving push
-----> Node.js app detected

/app/slug-compiler/buildpacks/nodejs2/vendor/json/json:425
  return runInNewContext("(" + JSON.stringify(datum) + ")" + lookupCode);
         ^
TypeError: Cannot read property 'node' of undefined
    at evalmachine.<anonymous>:1:118
    at lookupDatum (/app/slug-compiler/buildpacks/nodejs2/vendor/json/json:425:10)
    at Socket.<anonymous> (/app/slug-compiler/buildpacks/nodejs2/vendor/json/json:628:24)
    at Socket.emit (events.js:61:17)
    at Socket._onReadable (net.js:656:51)
    at IOWatcher.onReadable [as callback] (net.js:177:10)

/app/slug-compiler/buildpacks/nodejs2/vendor/json/json:425
  return runInNewContext("(" + JSON.stringify(datum) + ")" + lookupCode);
         ^
TypeError: Cannot read property 'npm' of undefined
    at evalmachine.<anonymous>:1:118
    at lookupDatum (/app/slug-compiler/buildpacks/nodejs2/vendor/json/json:425:10)
    at Socket.<anonymous> (/app/slug-compiler/buildpacks/nodejs2/vendor/json/json:628:24)
    at Socket.emit (events.js:61:17)
    at Socket._onReadable (net.js:656:51)
    at IOWatcher.onReadable [as callback] (net.js:177:10)
-----> Resolving engine versions
       Using Node.js version: 0.4.7
       Using npm version: 1.0.94
-----> Fetching Node.js binaries
-----> Vendoring node into slug
-----> Installing dependencies with npm

       [email protected] /tmp/build_1m5t2ah1oglfb/node_modules/express
       [email protected] /tmp/build_1m5t2ah1oglfb/node_modules/express/node_modules/connect
       [email protected] /tmp/build_1m5t2ah1oglfb/node_modules/express/node_modules/qs
       [email protected] /tmp/build_1m5t2ah1oglfb/node_modules/express/node_modules/mime
       [email protected] /tmp/build_1m5t2ah1oglfb/node_modules/express/node_modules/connect/node_modules/formidable
       [email protected] /tmp/build_1m5t2ah1oglfb/node_modules/express/node_modules/mkdirp
       [email protected] /tmp/build_1m5t2ah1oglfb/node_modules/jade
       [email protected] /tmp/build_1m5t2ah1oglfb/node_modules/jade/node_modules/commander
       [email protected] /tmp/build_1m5t2ah1oglfb/node_modules/jade/node_modules/mkdirp
       Dependencies installed
-----> Discovering process types
       Procfile declares types -> web
-----> Compiled slug size is 3.1MB
-----> Launching... done, v7

Answer 1

This was a heroku issue and appears to have gone away.