Rails3 app failed to push to Heroku. "Unrecognized error"

Things seem to go great, and then it chokes at the end. Observe:

$ git push heroku master
Counting objects: 12, done.
Delta compression using up to 2 threads.
Compressing objects: 100% (7/7), done.
Writing objects: 100% (7/7), 109.76 KiB, done.
Total 7 (delta 4), reused 0 (delta 0)

-----> Heroku receiving push
-----> Ruby/Rails app detected
-----> Detected Rails is not set to serve static_assets
Installing rails3_serve_static_assets... done
-----> Configure Rails 3 to disable x-sendfile
Installing rails3_disable_x_sendfile... done
-----> Configure Rails to log to stdout
Installing rails_log_stdout... done
-----> Gemfile detected, running Bundler version 1.0.7
Unresolved dependencies detected; Installing...
Using --without development:test
Installing rake (0.9.2) 
Installing multi_json (1.0.3) 
Installing activesupport (3.1.1.rc1) 
   Installing builder (3.0.0) 
   Installing i18n (开发者_如何学JAVA0.6.0) 
   Installing activemodel (3.1.1.rc1) 
   Installing erubis (2.7.0) 
   Installing rack (1.3.3) 
   Installing rack-cache (1.0.3) 
   Installing rack-mount (0.8.3) 
   Installing rack-test (0.6.1) 
   Installing hike (1.2.1) 
   Installing tilt (1.3.3) 
   Installing sprockets (2.0.0) 
   Installing actionpack (3.1.1.rc1) 
   Installing mime-types (1.16) 
   Installing polyglot (0.3.2) 
   Installing treetop (1.4.10) 
   Installing mail (2.3.0) 
   Installing actionmailer (3.1.1.rc1) 
   Installing arel (2.2.1) 
   Installing tzinfo (0.3.29) 
   Installing activerecord (3.1.1.rc1) 
   Installing activeresource (3.1.1.rc1) 
   Installing coffee-script-source (1.1.2) 
   Installing execjs (1.2.6) 
   Installing coffee-script (2.2.0) 
   Installing rack-ssl (1.3.2) 
   Installing rdoc (3.9.4) 
   Installing thor (0.14.6) 
   Installing railties (3.1.1.rc1) 
   Installing coffee-rails (3.1.1) 
   Installing jquery-rails (1.0.14) 
   Installing pg (0.11.0) with native extensions 
   Using bundler (1.0.7) 
   Installing rails (3.1.1.rc1) 
   Installing sass (3.1.7) 
   Installing sass-rails (3.1.2) 
   Installing sqlite3 (1.3.4) with native extensions 
   Installing uglifier (1.0.3) 
   Updating .gem files in vendor/cache
   Removing outdated .gem files from vendor/cache
     * spork-0.9.0.rc9.gem
   Your bundle is complete! It was installed into ./.bundle/gems/
-----> Compiled slug size is 14.4MB
-----> Launching...
 !     Heroku push rejected due to an unrecognized error.
 !     We've been notified, see http://support.heroku.com if the problem persists.


To git@heroku.com:myproject.git
 ! [remote rejected] master -> master (pre-receive hook declined)
error: failed to push some refs to 'git@heroku.com:myproject.git'

Before this, I was able to push to Heroku, but the app was failing to launch because I was missing the pg gem. So now the pg is in there correctly and the push fails. Any ideas on how I can fix this?

You should submit a ticket to support. Seems like they've had a similar issue in the past:

http://status.heroku.com/incident/52

At first glance, that spork gem looks suspicious. Are you segregating your development gems in a group in your Gemfile?

group :development, :test do
  gem 'spork'
end

you should check https://status.heroku.com/ first.

There's an open issue (https://status.heroku.com/incident/212) which was opened 54 minutes ago which relates to deployment issues - although it appears to be only Cedar apps affected now - but that's not to say it wasn't the full stack when the issue was created.