Rails: Could not find minitest-4.7.5 in any of the sources

Question

Here is a trouble: on my remote server command gem list shows:

some gems
minitest (4.7.5)  
....

bundle show minitest command shows:

/var/lib/gems/1.9.1/gems/minitest-4.7.5

bundle show rails shows the same directory

bundle -v - 1.6.2 (the latest version)

But I've an error: Could not find minitest-4.7.5 in any of the sources (Bundler::GemNotFound)

The steps I've made

• Delete Gemfile.lock and bundle install again
• Reinstall bundler
• Ruby version 2.1.2

Bundle install output shows Using minitest (4.7.5)

Answer 1

On the remote server run gem update bundler and after bundle install.