Why won't the bcrypt ruby gem install properly?

In recent versions bcrypt-ruby seems to use the GMP library.

So, on Linux something like this should help (command for Ubuntu 14.04):

sudo aptitude install libgmp-dev

Try removing ,'3.0.1' or try like this gem "bcrypt", "~> 3.1.1"

Hope it helps.

If not, from console try running gem install bcrypt

Actually a simple:

gem install bundler
gem install bcrypt-ruby

and then:

bundle update bcrypt-ruby
or bundle update bcrypt

Would've done the trick.

It's much the same way that you would upgrade rails. If you wanted to make sure you could also specify the latest bcrypt-ruby in your Gemfile. I just did this ten minutes ago so I know it works as of the date of this post... I was using ruby 1.9.3 p484