El Capitan upgrade: Library not loaded: /usr/local/lib/libmysqlclient.18.dylib

Question

Error:

/Users/askar/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/gems/mysql2-0.3.20/lib/mysql2.rb:31:in `require': dlopen(/Users/askar/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/extensions/x86_64-darwin-14/2.2.0-static/mysql2-0.3.20/mysql2/mysql2.bundle, 9): Library not loaded: /usr/local/lib/libmysqlclient.18.dylib (LoadError)
  Referenced from: /Users/askar/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/extensions/x86_64-darwin-14/2.2.0-static/mysql2-0.3.20/mysql2/mysql2.bundle
  Reason: image not found - /Users/askar/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/extensions/x86_64-darwin-14/2.2.0-static/mysql2-0.3.20/mysql2/mysql2.bundle

In Gemfile: gem 'mysql2'

$ ls -al /usr/local/lib/libmysql*

lrwxr-xr-x  1 askar  admin  49 Nov 13 10:48 /usr/local/lib/libmysqlclient.20.dylib -> ../Cellar/mysql/5.7.9/lib/libmysqlclient.20.dylib
lrwxr-xr-x  1 askar  admin  42 Nov 13 10:48 /usr/local/lib/libmysqlclient.a -> ../Cellar/mysql/5.7.9/lib/libmysqlclient.a
lrwxr-xr-x  1 askar  admin  46 Nov 13 10:48 /usr/local/lib/libmysqlclient.dylib -> ../Cellar/mysql/5.7.9/lib/libmysqlclient.dylib
lrwxr-xr-x  1 askar  admin  37 Nov 13 10:48 /usr/local/lib/libmysqld.a -> ../Cellar/mysql/5.7.9/lib/libmysqld.a
lrwxr-xr-x  1 askar  admin  44 Nov 13 10:48 /usr/local/lib/libmysqlservices.a -> ../Cellar/mysql/5.7.9/lib/libmysqlservices.a

$ ls -al /usr/local/Cellar/mysql/5.7.9/lib/

total 84392
drwxr-xr-x   9 askar  admin       306 Nov 12 22:16 .
drwxr-xr-x  14 askar  admin       476 Nov 13 10:48 ..
-r--r--r--   1 askar  admin   3780168 Nov 13 10:48 libmysqlclient.20.dylib
-r--r--r--   1 askar  admin   4280752 Nov 12 22:16 libmysqlclient.a
lrwxr-xr-x   1 askar  admin        23 Nov 12 22:16 libmysqlclient.dylib -> libmysqlclient.20.dylib
-r--r--r--   1 askar  admin  35126528 Nov 12 22:16 libmysqld.a
-r--r--r--   1 askar  admin      9048 Nov 12 22:16 libmysqlservices.a
drwxr-xr-x   3 askar  admin       102 Nov 13 10:48 pkgconfig
drwxr-xr-x  43 askar  admin      1462 Nov 12 22:17 plugin
drwxr-xr-x  43 askar  admin      1462 Nov 12 22:17 plugin

As you see I'm having libmysqlclient.20.dylib, it's 20 not 18, otherwise I'd follow the solution here.

I've recently upgraded to El Capitan but not sure it that's the cause.

UPDATE:

Thanks to @Rashmirathi for the hint to re-install the gem.

Just wanted to note, I needed also to specify in Gemfile as:

gem 'mysql2', '~> 0.3.18'

Otherwise I had error:

Specified 'mysql2' for database adapter, but the gem is not loaded. Add gem 'mysql2' to your Gemfile (and ensure its version is at the minimum required by ActiveRecord).

But finally I got error:

Mysql2::Error
Your password has expired. To log in you must change it using a client that supports expired passwords.

Which is solved by setting up a password again:

SET PASSWORD=PASSWORD('your_password');

Answer 1

I was getting the same issue earlier on, I fixed it by reinstalling the gem mysql2.