Heroku push rejected due to failure to install gems - ruby-on-rails

Question

C:\documents\projects\AJP\app>bundle update
Fetching gem metadata from http://rubygems.org/.......
Using rake (0.8.7)
Using abstract (1.0.0)
Using activesupport (3.0.7)
Using builder (2.1.2)
Using i18n (0.5.0)
Using activemodel (3.0.7)
Using erubis (2.6.6)
Using rack (1.2.5)
Using rack-mount (0.6.14)
Using rack-test (0.5.7)
Using tzinfo (0.3.33)
Using actionpack (3.0.7)
Using mime-types (1.18)
Using polyglot (0.3.3)
Using treetop (1.4.10)
Using mail (2.2.19)
Using actionmailer (3.0.7)
Using arel (2.0.10)
Using activerecord (3.0.7)
Using activeresource (3.0.7)
Using bundler (1.1.4)
Using thor (0.14.6)
Using railties (3.0.7)
Using rails (3.0.7)
Using acts-as-taggable-on (2.3.1)
Using annotate (2.4.0)
Using diff-lcs (1.1.3)
Using factory_girl (1.3.3)
Using factory_girl_rails (1.0)
Using faker (0.3.1)
Using gravatar_image_tag (1.0.0.pre2)
Using jquery-rails (1.0.19)
Using nested_form (0.2.0)
Using nokogiri (1.5.2)
Using pg (0.11.0)
Using rspec-core (2.5.2)
Using rspec-expectations (2.5.0)
Using rspec-mocks (2.5.0)
Using rspec (2.5.0)
Using rspec-rails (2.5.0)
Using webrat (0.7.1)
Using will_paginate (3.0.3)
Your bundle is updated! Use `bundle show [gemname]` to see where a bundled gem is installed.
C:\documents\projects\AJP\app>git st
# On branch master
nothing to commit (working directory clean)
C:\documents\projects\AJP\app>git ls-files
.gitignore
.settings/org.eclipse.core.resources.prefs
Gemfile
Gemfile.lock
README
...
Have run both bundle install and bundle update. Note also that Gemfile and Gemfile.lock files are in the committed files.
But then:
C:\documents\projects\AJP\app>git push heroku master
Enter passphrase for key '/c/Users/AJames/.ssh/id_rsa':
Counting objects: 46, done.
Delta compression using up to 2 threads.
Compressing objects: 100% (31/31), done.
Writing objects: 100% (31/31), 4.46 KiB, done.
Total 31 (delta 24), 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
Windows Gemfile.lock detected, ignoring it.
You have modified your Gemfile in development but did not check
the resulting snapshot (Gemfile.lock) into version control
You have added to the Gemfile:
* source: rubygems repository http://rubygems.org/
* rails (= 3.0.7)
* pg (= 0.11.0)
* gravatar_image_tag (= 1.0.0.pre2)
* will_paginate
* rake (= 0.8.7)
* jquery-rails
* nested_form
* acts-as-taggable-on
* rspec-rails (= 2.5.0)
* annotate (= 2.4.0)
* faker (= 0.3.1)
* rspec (= 2.5.0)
* webrat (= 0.7.1)
* factory_girl_rails (= 1.0)
FAILED: http://devcenter.heroku.com/articles/bundler
! Heroku push rejected, failed to install gems via Bundler
To git#heroku.com:ajpxvb.git
! [remote rejected] master -> master (pre-receive hook declined)
error: failed to push some refs to 'git#heroku.com:ajpxvb.git'
Any ideas please? Thanks.

Answer 1

One thing I noticed in the Heroku output is this:
"Windows Gemfile.lock detected, ignoring it."
I read a Heroku Dev Center Article on Bundler that notes the following regarding: Gemfile.lock
If the platforms section of your Gemfile contains Windows entries, such as mswin or mingw, then the Gemfile.lock file will be ignored.
By chance does your Gemfile contain the aforementioned sections and, if so, what happens if you remove/comment out the platform sections (just to test)?