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,

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

I experienced this issue:

Here's my solution:

Solution 1:

This solution works a lot of the time, simply update the gem causing the issue.

bundle update rack

Solution 2:

In some cases Solution 1 may not work, and you will need to edit your Gemfile.lock file.

Simply, open your Gemfile.lock file and then change the version to the update requested.

In my case, I had rack 2.0.7 defined in my Gemfile.lock file, but my application required rack 2.1.2, I simply had to modify it to rack 2.1.2 in the Gemfile.lock file.

I then had to uninstall the previous version of rack which is rack 2.0.7

 gem uninstall rack -v 2.0.7

And finally installed the new gem in production

bundle install --without development test

Solution 3:

In very rare cases Solution 1 and Solution 2 may not work, and you will need to edit your Gemfile before updating the gem.

In my case, the gem was puma, I had puma ~> 3.11 defined in my Gemfile, but my application required puma ~> 4.3.1. At this point running bundle update puma and editing my Gemfile.lock file didn't work, since puma ~> 3.11 version specified in the Gemfile would not allow an update to puma ~> 4.3.1.

I simply had to change the version of puma in the Gemfile to puma ~> 4.3.1 and then ran the command.

bundle update puma

That's all.

I hope this helps

Answer 3

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

Answer 4

These issues might arise if you are using local or global gemset for more than one project. Why not create seprate gemset for each project.

You can do this using rvm

Create new gemset

rvm gemset create new_test

rvm gemset use new_test

bundle install

Answer 5

You can simply run below cmd to get the latest rack installed in server to fix the issue:

gem install rack

Answer 6

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