Bundle install fails with: Bundler could not find compatible versions for gem "railties":

Question

I currently can't run bundle install. It always fails:

$ bundle install
Fetching source index from https://rubygems.org/
Updating git://github.com/gregbell/active_admin.git
fatal: Could not parse object 'a9949c1524205928b18597f840e83478ba97c2ef'.
Git error: command `git reset --hard a9949c1524205928b18597f840e83478ba97c2ef` in directory /Users/noxoc/.rvm/gems/ruby-1.9.3-p385@tp-usevalue/bundler/gems/active_admin-a9949c152420 has failed.
If this error persists you could try removing the cache directory '/Users/noxoc/.rvm/gems/ruby-1.9.3-p385@tp-usevalue/cache/bundler/git/active_admin-d67faab65e9b74efbc8efb4a777a851e9f78b2ca'

I already tried to remove the cache directory as advised. This is my Gemfile (sorted, comments stripped):

source 'https://rubygems.org'

gem 'active_link_to'
gem 'activeadmin'
gem 'coffee-rails'
gem 'compass-rails'
gem 'debugger', group: [:development, :test]
gem 'devise',              github: 'plataformatec/devise'
gem 'formtastic',          github: 'justinfrench/formtastic'
gem 'inherited_resources', github: 'josevalim/inherited_resources'
gem 'jbuilder', '~> 1.2'
gem 'jquery-rails'
gem 'jquery-turbolinks'
gem 'rails'
gem 'rails-i18n', '~> 4.0.0.pre' # For 4.0.x
gem 'ransack'
gem 'responders',          github: 'plataformatec/responders'
gem 'sass-rails'
gem 'simple_form'
gem 'sqlite3'
gem 'turbolinks'
gem 'uglifier', '>= 1.3.0'

group :doc do
  gem 'sdoc', require: false
end

group :development, :test do
  gem "rb-fsevent", "~> 0.9.1"
  gem "guard", "1.6.2"
  gem "guard-spork"
  gem "guard-rspec", "2.5.1"
  gem "rspec-rails", "2.13.1"
  gem "shoulda-matchers", "2.1.0"
  gem "capybara", "2.1.0"
  gem "launchy", "2.2.0"
  gem 'spork-rails', :github => 'sporkrb/spork-rails'
  gem "thin"
end

What really confuses me, is that it worked just fine a couple of days ago.

UPDATE:

As zrl3dx suggested, I removed the Gemfile.lock and ran bundle again - which results in this error:

$ bundle
Updating git://github.com/gregbell/active_admin.git
Updating git://github.com/milgner/compass-rails.git
Updating git://github.com/plataformatec/devise.git
Updating git://github.com/justinfrench/formtastic.git
Updating git://github.com/josevalim/inherited_resources.git
Updating git://github.com/ernie/ransack.git
Updating git://github.com/plataformatec/responders.git
Updating git://github.com/sporkrb/spork-rails.git
Fetching gem metadata from https://rubygems.org/.........
Fetching gem metadata from https://rubygems.org/..
Resolving dependencies...
Bundler could not find compatible versions for gem "ransack":
  In Gemfile:
    activeadmin (>= 0) ruby depends on
      ransack (>= 1.0.0) ruby

    ransack (0.7.3)

Bundler could not find compatible versions for gem "railties":
  In Gemfile:
    rails (= 4.0.0) ruby depends on
      railties (= 4.0.0) ruby

    coffee-rails (~> 4.0.0) ruby depends on
      railties (4.0.0.rc2)

Answer 1

If found this worked for me:

unset GIT_DIR

Found from https://github.com/mislav/git-deploy/issues/27

Answer 2

The rails4 branch of Active Admin referenced in the accepted answer no longer exists. It has been merged into master but has not yet been released on rubygems. This gemfile entry will reference the newest commit with rails4 support.

gem 'activeadmin', github: 'gregbell/active_admin', :ref=> 'fe7d6a6e1bafc9e9dd765dfb3a09245ccd0b3cfd'

Answer 3

Try removing Gemfile.lock and doing bundle again.

Try adding to Gemfile:

gem 'coffee-rails', git: 'git://github.com/rails/coffee-rails.git'

instead of:

gem 'coffe-rails'

Edit:

Ok, I have copied it locally and tried to resolve, my changes:

gem 'coffee-rails', git: 'git://github.com/rails/coffee-rails.git'
gem 'activeadmin',         github: 'gregbell/active_admin', branch: 'rails4'
gem 'rails', git: 'https://github.com/rails/rails.git', branch: '4-0-stable'
gem 'devise'
gem 'ransack'
gem 'sass-rails', git: 'https://github.com/rails/sass-rails.git'

and now it checks out, at least here.