Ruby on windows causes error Cannot load such file bcrypt_ext - ruby-on-rails

Question

Trying to run ruby on my Windows 7 machine whenever i go to rails s or rake db:migrate i get the following error Cannot load such file bcrypt_ext.
My ruby version is 2.2.1 my rails version is 4.2.0 and the bcrypt version is 3.1.10. All the gems install correctly when i run bundle install however whenever i try to rake it gives me that error. Any help would be greatly appreciated

Answer 1

You need to use what it says here: https://www.alib.jp/entries/bcrypt_ext_load_error_on_ruby21x
C:\> gem install --no-ri --no-rdoc bcrypt
C:\> cd (path to gems root)\bcrypt-3.1.7-x86-mingw32\ext\mri
C:\(path to gems root)\bcrypt-3.1.7-x86-mingw32\ext\mri> ruby extconf.rb
C:\(path to gems root)\bcrypt-3.1.7-x86-mingw32\ext\mri> make
C:\(path to gems root)\bcrypt-3.1.7-x86-mingw32\ext\mri> make install

Answer 2

I meet the same problem in Window 8.1 64bit , Ruby 2.3.3 64bit , Rails 4.2.10.
My quick solution :
Step 1 : Remove all bcrypt in gem : gem uninstall bcrypt ( choose option 3 if existed (remove all))
Step 2 : Install bcrypt again : gem install bcrypt
Then check version of bcrypt : gem list bcrypt
Step 3 : In Gemfile of your project, add : gem 'bcrypt', '3.1.11', platforms: [:ruby, :x64_mingw]
notice : change the suitable version of your bcrypt (my version : 3.1.11)
Step 4 : Run command in the path of your project : bundle install
Step 5 : Remove the unneeded bcrypt :
Run command : gem uninstall bcrypt
You can see some version of bcrypt , you should keep one version : bcrypt-[your-version] . (Remove all version : bcrypt-[your-version]-x64-mingw32 . In mycase , remove : bcrypt-3.1.11-x64-mingw32)
Restart Rails sever , done
I think this proplem because when we install bcrypt , we didn't specify 64bit or 32bit , it is not compatible with window or ruby ( 64bit or 32bit )

Answer 3

For Windows 10, bcrypt 3.1.11 now works, checked in 24144
steps:
shut down all rails servers
uninstall all versions of bcrypt
manually install v3.1.1 (gem install bcrypt -v '3.1.11')
update gem files of projects
current versions
ruby 2.2.4p230 (2015-12-16 revision 53155) [i386-mingw32]
OS Name: Microsoft Windows 10 Pro
OS Version: 10.0.10586 N/A Build 10586

Answer 4

The dirty quick workaround is to install the mri version with
gem install bcrypt --platform=ruby
worked for me.
Fetching: bcrypt-3.1.11.gem (100%)
Temporarily enhancing PATH to include DevKit...
Building native extensions. This could take a while...
Successfully installed bcrypt-3.1.11
source:
topac commented on Apr 17, 2015
https://github.com/codahale/bcrypt-ruby/issues/116

Answer 5

Rich Peck solution worked for me with a small update. Make sure the devkit is included in the environment path.(Check it by typing path in the command prompt) If its not included,you need to add the devkit/bin and devkit/mingw/bin paths to your PATH var.
Otherwise - make: x86_64-w64-mingw32-gcc: Command not found - error will be thrown while you make the file.
Once the error is fixed, then i am able to make the file and the bcrypt_ext issue is solved.

Answer 6

Most likely the compiled gem binaries don't contain binaries for Ruby 2.2.1. This is because there is a problem with cross-compiling Ruby with a Windows target. See this answer for more details.
The best alternative is to downgrade to Ruby 2.1.5.
You can try to compile the gem yourself, but that's a totally different beast. In some cases, like nokogiri, it's not even possible.