Error installing mysql2 adapter: Please install the mysql2 adapter: `gem install activerecord-mysql2-adapter` (cannot load such file — mysql2/mysql2)

Question

I am getting this error when running Redmine2.3-stable, and subsequently unable to install the mysql2 adapter successfully.

This is the error:

    Please install the mysql2 adapter: `gem install activerecord-mysql2-adapter` (cannot load such file -- mysql2/mysql2)

I'm getting this when running the website, via passenger, and when running rake db:migrate

The adapter is installed:

gem list

* LOCAL GEMS *

actionmailer (3.2.13)
actionpack (3.2.13)
activemodel (3.2.13)
activerecord (3.2.13)
activerecord-mysql2-adapter (0.0.3)
activeresource (3.2.13)
activesupport (3.2.13)
afm (0.2.0)
arel (3.0.2)
Ascii85 (1.0.2)
bigdecimal (1.1.0)
builder (3.0.4, 3.0.0)
bundler (1.3.4)
coderay (1.0.9)
daemon_controller (1.1.2)
daemons (1.1.9)
erubis (2.7.0)
eventmachine (1.0.3)
fastthread (1.0.7)
hashery (2.1.0)
hike (1.2.1)
holidays (1.0.5)
i18n (0.6.1)
icalendar (1.2.3)
io-console (0.3)
journey (1.0.4)
jquery-rails (2.0.3)
json (1.7.7, 1.5.4)
mail (2.5.3)
mime-types (1.21)
minitest (4.7.0, 2.5.1)
multi_json (1.7.2)
mysql2 (0.3.11)
net-ldap (0.3.1)
nokogiri (1.5.9)
open-uri-cached (0.0.5)
passenger (3.0.19)
pdf-reader (1.3.2)
polyglot (0.3.3)
prawn (0.12.0)
rack (1.4.5)
rack-cache (1.2)
rack-openid (1.3.1)
rack-ssl (1.3.3)
rack-test (0.6.2)
rails (3.2.13)
railties (3.2.13)
rake (10.0.4, 0.9.2.2)
rdoc (3.12.2, 3.9.4)
ruby-openid (2.1.8)
ruby-rc4 (0.1.5)
rubygems-update (2.0.3)
sprockets (2.2.2)
thin (1.5.1)
thor (0.17.0)
tilt (1.3.6)
treetop (1.4.12)
ttfunk (1.0.3)
tzinfo (0.3.37)

ruby -v

ruby 1.9.3p194 (2012-04-20 revision 35410) [x86_64-linux]

gem env

- RUBYGEMS VERSION: 2.0.3
- RUBY VERSION: 1.9.3 (2012-04-20 patchlevel 194) [x86_64-linux]
- INSTALLATION DIRECTORY: /usr/local/lib/ruby/gems/1.9.1
- RUBY EXECUTABLE: /usr/local/bin/ruby
- EXECUTABLE DIRECTORY: /usr/local/bin
- RUBYGEMS PLATFORMS:
  - ruby
  - x86_64-linux
- GEM PATHS:
   - /usr/local/lib/ruby/gems/1.9.1
   - /root/.gem/ruby/1.9.1
- GEM CONFIGURATION:
   - :update_sources => true
   - :verbose => true
   - :backtrace => false
   - :bulk_threshold => 1000
- REMOTE SOURCES:
   - https://rubygems.org/

I tried forcing redmine to rails3.2.2 by editing the Gemfile, per a suggestion here:

Rails 3.2.2 mysql2 adapter Error

Notes

I had to force the gem mysql2 bundle install to work by using the command below ( i was getting errors about errormsg.h).

sudo gem install activerecord-mysql2-adapter -- --srcdir=/usr/include/mysql/

Any thoughts?

I moved back down to Ruby 1.8.7 and don't have this problem anymore. — Patrick Cummins
Check if you're using adapter: mysql2 instead of adapter: mysql in your database.yml. — Marcelo De Polli

chinnabujji chinnabujji · Accepted Answer · 2013-05-22T11:25:13

Include mysql2 gem in your Gemfile and also change adapter in database.yml to mysql2 and then do the bundle install. It will solve your problem ..

Error installing mysql2 adapter: Please install the mysql2 adapter: `gem install activerecord-mysql2-adapter` (cannot load such file — mysql2/mysql2)

1 Answers