You have already activated rack 1.6.0, but your Gemfile requires rack 1.6.4

Question

Similar to problem with rack 1.3.2. You have already activated rack 1.3.2, but your Gemfile requires rack 1.2.3 -- I'm experiencing You have already activated rack 1.6.0, but your Gemfile requires rack 1.6.4 when attempting to run Rails (4.2) in production with Puma and Nginx.

bundle update rake nor rm Gemfile.lock && bundle install seem to help, the only solution I have so far is manually changing rack (1.6.4) to rack (1.6.0) in Gemfile.lock.

Answer 1

you need to uninstall one version of rack which is not required.

Do this please

gem uninstall rack -v 1.6.0

Reference: How to force rack to work around the usual "You have already activated rack..." bug?

Answer 2

One experienced Rails developer highly recommends using binstubs. Have it installed by:

bundle install --binstubs

and run it via relative path:

./bin/rails server

or what is most recommended update PATH and forget about bundler issues:

export PATH="./bin:$PATH"
rails server

Answer 3

Run it like this: bundle exec rails s. This will use settings from your Gemfile.lock