Why is rails admin not installed in rails 5?

Question

Ruby on Rails

When I add rails_admin to gemfile. and make a bundle. the following error appears:

Bundler could not find compatible versions for gem "rails":
  In snapshot (Gemfile.lock):
    rails (= 5.0.0)

  In Gemfile:
    rails (~> 5.0.0)

    rails_admin was resolved to 0.0.1, which depends on
      rails (~> 3.1)

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

what it is?

Answer 1

Maybe try installing via rails-5 branch?
Here 's more research on how to match rails_admin dependencies

gem 'rails_admin', github: 'sferik/rails_admin'
# Use github rack-pjax to fix dependency versioning issue with Rails 5
# https://github.com/sferik/rails_admin/issues/2532
gem 'rack-pjax', github: 'afcapel/rack-pjax'
# Use forked remotipart until following issues are resolved
# https://github.com/JangoSteve/remotipart/issues/139
# https://github.com/sferik/rails_admin/issues/2532
gem 'remotipart', github: 'mshibuya/remotipart', ref: '3a6acb3'

Unstable of course, but suddenly you can live.

Answer 2

Still written in the log, what is there to explain?
https://github.com/sferik/rails_admin/issues/2532

Answer 3

I had such a problem. I decided to install the gem through the terminal.
gem install rails_admin