sass-rails requires sprockets 2.0.0 but rails 4.1.

Question

This question already has an answer here:

• Updating from Rails 4.0 to 4.1 gives sass-rails railties version conflicts 4 answers

I'm trying to upgrade my application from rails 3.2.16 to rails 4.1.0, I get into troubles right at the beginning when I try to call the bundler:

Bundler could not find compatible versions for gem "sprockets":
  In Gemfile:
    sass-rails (>= 0) ruby depends on
      sprockets (~> 2.0.0) ruby

    rails (= 4.1.0) ruby depends on
      sprockets-rails (~> 2.0) ruby depends on
        sprockets (2.12.1)

Bundler could not find compatible versions for gem "sprockets-rails":
  In Gemfile:
    sass-rails (>= 0) ruby depends on
      sprockets-rails (~> 2.0.0) ruby

    rails (= 4.1.0) ruby depends on
      sprockets-rails (2.1.3)

Bundler could not find compatible versions for gem "railties":
  In Gemfile:
    sass-rails (>= 0) ruby depends on
      railties (~> 3.1.0) ruby

    rails (= 4.1.0) ruby depends on
      railties (4.1.0)

and (part) of my Gemfile:

gem 'rails', '4.1.0'
gem 'mysql2'
gem "rake"
gem "less-rails" #Sprockets (what Rails 3.1 uses for its asset pipeline) supports LESS
gem 'sass-rails'

Answer 1

Some older versions of Bundler have a bug that can cause this failure to resolve. Updating to the latest version might help.

Run this to update:

gem install bundler