LoadError: cannot load such file — bcrypt_ext

I got a bcrypt error when using Devise on Windows 10 and Ruby 2.2.2p95 and rails 4.2.5

You should have DevKit installed and configured correctly to recompile the gem.

LoadError: cannot load such file -- bcrypt_ext

1	LoadError: cannot load such file -- bcrypt_ext

Firt stop your server and remove every bcrypt gem or bcrypt-ruby gem.

C:\>gem uninstall bcrypt
You have requested to uninstall the gem:
        bcrypt-3.1.10-x86-mingw32

bcrypt-ruby-3.1.5 depends on bcrypt (>= 3.1.3)
devise-3.5.2 depends on bcrypt (~> 3.0)
If you remove this gem, these dependencies will not be met.
Continue with Uninstall? [yN]  y
Successfully uninstalled bcrypt-3.1.10-x86-mingw32

C:\>gem uninstall bcrypt

You have requested to uninstall the gem:

bcrypt-3.1.10-x86-mingw32

bcrypt-ruby-3.1.5 depends on bcrypt (>= 3.1.3)

devise-3.5.2 depends on bcrypt (~> 3.0)

If you remove this gem, these dependencies will not be met.

Continue with Uninstall? [yN] y

Successfully uninstalled bcrypt-3.1.10-x86-mingw32

Don’t forget to include bcrypt in your Gemfile

gem 'bcrypt'

1	gem 'bcrypt'

make a bundle update and recompile the gem like this

C:\<Ruby Path>\lib\ruby\gems\bcrypt-3.1.10-x86-mingw32\ext\mri> ruby extconf.rb
C:\<Ruby Path>\lib\ruby\gems\bcrypt-3.1.10-x86-mingw32\ext\mri> make
generating bcrypt_ext-i386-mingw32.def
compiling bcrypt_ext.c
compiling crypt.c
compiling crypt_blowfish.c
compiling crypt_gensalt.c
compiling wrapper.c
linking shared-object bcrypt_ext.so

(if make is not recognized as a valid command, execute this command and do a make again
C:\<Current Folder> C:\<DevKit Path>\devkitvars.bat
Adding the DevKit to PATH...)

C:\<Ruby Path>\lib\ruby\gems\bcrypt-3.1.10-x86-mingw32\ext\mri> make install
/usr/bin/install -c -m 0755 bcrypt_ext.so /C/<Ruby Path>/lib/ruby/site_ruby/2.2.0/i386-msvcrt

C:\<Ruby Path>\lib\ruby\gems\bcrypt-3.1.10-x86-mingw32\ext\mri> ruby extconf.rb

C:\<Ruby Path>\lib\ruby\gems\bcrypt-3.1.10-x86-mingw32\ext\mri> make

generating bcrypt_ext-i386-mingw32.def

compiling bcrypt_ext.c

compiling crypt.c

compiling crypt_blowfish.c

compiling crypt_gensalt.c

compiling wrapper.c

linking shared-object bcrypt_ext.so

(if make is not recognized as a valid command, execute this command and do a make again

C:\<Current Folder> C:\<DevKit Path>\devkitvars.bat

Adding the DevKit to PATH...)

C:\<Ruby Path>\lib\ruby\gems\bcrypt-3.1.10-x86-mingw32\ext\mri> make install

/usr/bin/install -c -m 0755 bcrypt_ext.so /C/<Ruby Path>/lib/ruby/site_ruby/2.2.0/i386-msvcrt

Restart your server.

It should do the trick !

5 Thoughts on “LoadError: cannot load such file — bcrypt_ext”

Alfonso on November 9, 2016 at 15:09 said:

Awesome, at least a solution that actually worked out.

Thank’s a lot for this!!

Reply↓
Emeka on January 16, 2017 at 02:25 said:

i cant do make for some reason im in the right the path but the make command doesnt work
it says it has no target

Reply↓
jyothsna on February 11, 2017 at 13:49 said:

thanks.it worked.

Reply↓
carterax on October 5, 2017 at 12:22 said:

Works like a charm thanks a whole lot. Page Bookmarked

Reply↓
Darshan on August 7, 2020 at 13:12 said:

For bcrypt + bitnami
1) cd C:\Bitnami\rubystack-2.3.6-1\ruby\lib\ruby\gems\2.3.0\gems\bcrypt-3.1.11-x86-mingw32\ext\mri
2) load bitnami environment using below command
CALL “C:\Bitnami\rubystack-2.3.6-1\scripts\setenv.bat” (edited)
3) ruby extconf.rb
4) C:\Bitnami\rubystack-2.3.6-1\DevKit\devkitvars.bat
5)make install

Reply↓