rails error Bundler could not find compatible versions for gem gem “spree_backend”

Question

I want to configure email setting in spree I add this gem according to this tutorial https://guides.spreecommerce.com/user/configuring_mail_methods.html

  gem 'spree_mail_settings', github: 'spree-contrib/spree_mail_settings', branch: 'master'

But running bundle install gives me the following error:

Bundler could not find compatible versions for gem "spree_backend":
  In snapshot (Gemfile.lock):
    spree_backend (= 3.0.7)

  In Gemfile:
    spree (~> 3.0.7) was resolved to 3.0.7, which depends on
      spree_backend (= 3.0.7)

    spree_mail_settings was resolved to 2.2.0, which depends on
      spree_backend (~> 3.1.0.beta)

Running `bundle update` will rebuild your snapshot from scratch, using only
the gems in your Gemfile, which may resolve the conflict.

Running bundle update gives me this:

Bundler could not find compatible versions for gem "spree_backend":
  In Gemfile:
    spree_mail_settings was resolved to 2.2.0, which depends on
      spree_backend (~> 3.1.0.beta)

Could not find gem 'spree_backend (~> 3.1.0.beta)', which is required by gem
'spree_mail_settings', in any of the sources.

in my gemfile I have:

gem 'spree', '~> 3.0.7'
gem 'spree_gateway', '~> 3.0.0'
gem 'spree_auth_devise', '~> 3.0.0'
gem 'spree_i18n', git: 'git://github.com/spree/spree_i18n.git', branch: '3-0-stable'
gem 'spree_mail_settings', github: 'spree-contrib/spree_mail_settings', branch: 'master'

I tried to write like this gem 'spree', '~> 3.1.0' but it didn't work

Answer 1

~> 3.0.7 is equivalent to >= 3.0.7 and <3.1

Rather than trying to tease apart what is and isn't compatible, I would install it like:

gem 'spree'
gem 'spree_gateway'
gem 'spree_auth_devise'
gem 'spree_i18n', git: 'git://github.com/spree/spree_i18n.git', branch: '3-    0-stable'
gem 'spree_mail_settings', github: 'spree-contrib/spree_mail_settings', branch: 'master'

then I'd bundle install and bundle update. I'd then check the gemfile.lock and see what the gems versioned themselves to. Hopefully it resolves appropriately.

Answer 2

Delete your Gemfile.lock file then run bundle install and bundle update . I'm not assure this options should work,just try it.