When I try to run Rake (also with Rails commands) commands I got this error :
Rake aborted! cannot load such file -- arel/visitor/mysql
/config/application.rb:7:in <top (required)>
/Rakefile:4:in 'require_relative'
MySql database works perfectly, and I've added gem 'mysql2' in Gemfile.
Using --trace argument :
rake aborted!
LoadError: cannot load such file -- arel/visitors/mysql
/home/sneffar/.rbenv/versions/2.6.6/lib/ruby/gems/2.6.0/gems/activesupport-6.0.3.1/lib/active_support/dependencies.rb:324:in `require'
/home/sneffar/.rbenv/versions/2.6.6/lib/ruby/gems/2.6.0/gems/activesupport-6.0.3.1/lib/active_support/dependencies.rb:324:in `block in require'
/home/sneffar/.rbenv/versions/2.6.6/lib/ruby/gems/2.6.0/gems/activesupport-6.0.3.1/lib/active_support/dependencies.rb:291:in `load_dependency'
/home/sneffar/.rbenv/versions/2.6.6/lib/ruby/gems/2.6.0/gems/activesupport-6.0.3.1/lib/active_support/dependencies.rb:324:in `require'
/home/sneffar/.rbenv/versions/2.6.6/lib/ruby/gems/2.6.0/gems/activerecord-6.0.3.1/lib/arel/visitors.rb:8:in `<top (required)>'
/home/sneffar/.rbenv/versions/2.6.6/lib/ruby/gems/2.6.0/gems/activesupport-6.0.3.1/lib/active_support/dependencies.rb:324:in `require'
/home/sneffar/.rbenv/versions/2.6.6/lib/ruby/gems/2.6.0/gems/activesupport-6.0.3.1/lib/active_support/dependencies.rb:324:in `block in require'
/home/sneffar/.rbenv/versions/2.6.6/lib/ruby/gems/2.6.0/gems/activesupport-6.0.3.1/lib/active_support/dependencies.rb:291:in `load_dependency'
/home/sneffar/.rbenv/versions/2.6.6/lib/ruby/gems/2.6.0/gems/activesupport-6.0.3.1/lib/active_support/dependencies.rb:324:in `require'
/home/sneffar/.rbenv/versions/2.6.6/lib/ruby/gems/2.6.0/gems/activerecord-6.0.3.1/lib/arel.rb:17:in `<top (required)>'
/home/sneffar/.rbenv/versions/2.6.6/lib/ruby/gems/2.6.0/gems/activesupport-6.0.3.1/lib/active_support/dependencies.rb:324:in `require'
/home/sneffar/.rbenv/versions/2.6.6/lib/ruby/gems/2.6.0/gems/activesupport-6.0.3.1/lib/active_support/dependencies.rb:324:in `block in require'
/home/sneffar/.rbenv/versions/2.6.6/lib/ruby/gems/2.6.0/gems/activesupport-6.0.3.1/lib/active_support/dependencies.rb:291:in `load_dependency'
/home/sneffar/.rbenv/versions/2.6.6/lib/ruby/gems/2.6.0/gems/activesupport-6.0.3.1/lib/active_support/dependencies.rb:324:in `require'
/home/sneffar/.rbenv/versions/2.6.6/lib/ruby/gems/2.6.0/gems/activerecord-6.0.3.1/lib/active_record.rb:29:in `<top (required)>'
/home/sneffar/.rbenv/versions/2.6.6/lib/ruby/gems/2.6.0/gems/activesupport-6.0.3.1/lib/active_support/dependencies.rb:324:in `require'
/home/sneffar/.rbenv/versions/2.6.6/lib/ruby/gems/2.6.0/gems/activesupport-6.0.3.1/lib/active_support/dependencies.rb:324:in `block in require'
/home/sneffar/.rbenv/versions/2.6.6/lib/ruby/gems/2.6.0/gems/activesupport-6.0.3.1/lib/active_support/dependencies.rb:291:in `load_dependency'
/home/sneffar/.rbenv/versions/2.6.6/lib/ruby/gems/2.6.0/gems/activesupport-6.0.3.1/lib/active_support/dependencies.rb:324:in `require'
/home/sneffar/.rbenv/versions/2.6.6/lib/ruby/gems/2.6.0/gems/activerecord-6.0.3.1/lib/active_record/railtie.rb:3:in `<top (required)>'
/home/sneffar/.rbenv/versions/2.6.6/lib/ruby/gems/2.6.0/gems/activesupport-6.0.3.1/lib/active_support/dependencies.rb:324:in `require'
/home/sneffar/.rbenv/versions/2.6.6/lib/ruby/gems/2.6.0/gems/activesupport-6.0.3.1/lib/active_support/dependencies.rb:324:in `block in require'
/home/sneffar/.rbenv/versions/2.6.6/lib/ruby/gems/2.6.0/gems/activesupport-6.0.3.1/lib/active_support/dependencies.rb:291:in `load_dependency'
/home/sneffar/.rbenv/versions/2.6.6/lib/ruby/gems/2.6.0/gems/activesupport-6.0.3.1/lib/active_support/dependencies.rb:324:in `require'
/home/sneffar/working-dir/permission/config/application.rb:7:in `<top (required)>'
/home/sneffar/working-dir/permission/Rakefile:4:in `require_relative'
/home/sneffar/working-dir/permission/Rakefile:4:in `<top (required)>'
/home/sneffar/.rbenv/versions/2.6.6/lib/ruby/gems/2.6.0/gems/rake-13.0.1/lib/rake/rake_module.rb:29:in `load'
/home/sneffar/.rbenv/versions/2.6.6/lib/ruby/gems/2.6.0/gems/rake-13.0.1/lib/rake/rake_module.rb:29:in `load_rakefile'
/home/sneffar/.rbenv/versions/2.6.6/lib/ruby/gems/2.6.0/gems/rake-13.0.1/lib/rake/application.rb:703:in `raw_load_rakefile'
/home/sneffar/.rbenv/versions/2.6.6/lib/ruby/gems/2.6.0/gems/rake-13.0.1/lib/rake/application.rb:104:in `block in load_rakefile'
/home/sneffar/.rbenv/versions/2.6.6/lib/ruby/gems/2.6.0/gems/rake-13.0.1/lib/rake/application.rb:186:in `standard_exception_handling'
/home/sneffar/.rbenv/versions/2.6.6/lib/ruby/gems/2.6.0/gems/rake-13.0.1/lib/rake/application.rb:103:in `load_rakefile'
/home/sneffar/.rbenv/versions/2.6.6/lib/ruby/gems/2.6.0/gems/rake-13.0.1/lib/rake/application.rb:82:in `block in run'
/home/sneffar/.rbenv/versions/2.6.6/lib/ruby/gems/2.6.0/gems/rake-13.0.1/lib/rake/application.rb:186:in `standard_exception_handling'
/home/sneffar/.rbenv/versions/2.6.6/lib/ruby/gems/2.6.0/gems/rake-13.0.1/lib/rake/application.rb:80:in `run'
/home/sneffar/.rbenv/versions/2.6.6/lib/ruby/gems/2.6.0/gems/rake-13.0.1/exe/rake:27:in `<top (required)>'
/home/sneffar/.rbenv/versions/2.6.6/bin/rake:23:in `load'
/home/sneffar/.rbenv/versions/2.6.6/bin/rake:23:in `<main>'
Ruby --version : 2.6.6
Rails --version : 6.0.3.1
Rake --version: 13.0.1
I think you should remove arel:
gem uninstall arel
After that run:
bundle install
This should fix problem.
I also faced with this and agree with Nezir.
I believe that in my case, this happened because of such actions:
MySQL 5.7.30 -> MySQL 8.0.20 -> MySQL 5.7.30
The first time I had MySQL 5.7.30 it was fine with
bundle exec rake db:create db:structure:load
I faced this error while working with a legacy application, and here is the solution which worked for me. Hope this will work for you.
https://gist.github.com/SahSantoshh/fffbfbaa91f82b46ef8aa39922ee889e
Uninstall ruby
reinstall ruby
if db is running then It's fine if not, then run MySQL 5.7 using docker https://gist.github.com/SahSantoshh/8ff41ce4dd57305358e98d43adff76b1
hit bundle
run rake db:migrate
Related
I am trying to install redmine-3.4.2 on CentOS Linux release 7.3.1611 (Core)
Downloaded and extracted redmine-3.4.2 created database.yml & configuration.yml
Installed ruby & dependence using
yum install -y gcc-c++ rubygems ruby-devel ImageMagick-devel ImageMagick
Then done successfully completed gem install bundler and bundle install --without development test
Finally getting error while running bundle exec rake generate_secret_token with RAILS_ENV=production REDMINE_LANG=en
My Ruby gem version as follows:-
Ruby : ruby 2.0.0p648 (2015-12-16) [x86_64-linux]
Gem : 2.0.14.1
Rails : Rails 4.2.8
bundle exec rake generate_secret_token --trace
rake aborted!
LoadError: cannot load such file -- json
/usr/local/share/gems/gems/activesupport-4.2.8/lib/active_support/core_ext/object/json.rb:2:in 'require'
/usr/local/share/gems/gems/activesupport-4.2.8/lib/active_support/core_ext/object/json.rb:2:in '<top (required)>'
/usr/local/share/gems/gems/activesupport-4.2.8/lib/active_support/core_ext/object.rb:12:in `require'
/usr/local/share/gems/gems/activesupport-4.2.8/lib/active_support/core_ext/object.rb:12:in `<top (required)>'
/usr/local/share/gems/gems/railties-4.2.8/lib/rails/configuration.rb:2:in `require'
/usr/local/share/gems/gems/railties-4.2.8/lib/rails/configuration.rb:2:in `<top (required)>'
/usr/local/share/gems/gems/railties-4.2.8/lib/rails/railtie.rb:2:in `require'
/usr/local/share/gems/gems/railties-4.2.8/lib/rails/railtie.rb:2:in `<top (required)>'
/usr/local/share/gems/gems/railties-4.2.8/lib/rails/engine.rb:1:in `require'
/usr/local/share/gems/gems/railties-4.2.8/lib/rails/engine.rb:1:in `<top (required)>'
/usr/local/share/gems/gems/railties-4.2.8/lib/rails/application.rb:7:in `require'
/usr/local/share/gems/gems/railties-4.2.8/lib/rails/application.rb:7:in `<top (required)>'
/usr/local/share/gems/gems/railties-4.2.8/lib/rails.rb:11:in `require'
/usr/local/share/gems/gems/railties-4.2.8/lib/rails.rb:11:in `<top (required)>'
/usr/local/share/gems/gems/railties-4.2.8/lib/rails/all.rb:1:in `require'
/usr/local/share/gems/gems/railties-4.2.8/lib/rails/all.rb:1:in `<top (required)>'
/opt/APPS/redmine-3.4.2/config/application.rb:3:in `require'
/opt/APPS/redmine-3.4.2/config/application.rb:3:in `<top (required)>'
/opt/APPS/redmine-3.4.2/Rakefile:5:in `require'
/opt/APPS/redmine-3.4.2/Rakefile:5:in `<top (required)>'
/usr/local/share/gems/gems/rake-12.0.0/lib/rake/rake_module.rb:28:in `load'
/usr/local/share/gems/gems/rake-12.0.0/lib/rake/rake_module.rb:28:in `load_rakefile'
/usr/local/share/gems/gems/rake-12.0.0/lib/rake/application.rb:687:in `raw_load_rakefile'
/usr/local/share/gems/gems/rake-12.0.0/lib/rake/application.rb:96:in `block in load_rakefile'
/usr/local/share/gems/gems/rake-12.0.0/lib/rake/application.rb:178:in `standard_exception_handling'
/usr/local/share/gems/gems/rake-12.0.0/lib/rake/application.rb:95:in `load_rakefile'
/usr/local/share/gems/gems/rake-12.0.0/lib/rake/application.rb:79:in `block in run'
/usr/local/share/gems/gems/rake-12.0.0/lib/rake/application.rb:178:in `standard_exception_handling'
/usr/local/share/gems/gems/rake-12.0.0/lib/rake/application.rb:77:in `run'
/usr/local/share/gems/gems/rake-12.0.0/exe/rake:27:in `<top (required)>'
/usr/local/bin/rake:23:in `load'
/usr/local/bin/rake:23:in `<top (required)>'
/usr/local/share/gems/gems/bundler-1.15.4/lib/bundler/cli/exec.rb:74:in `load'
/usr/local/share/gems/gems/bundler-1.15.4/lib/bundler/cli/exec.rb:74:in `kernel_load'
/usr/local/share/gems/gems/bundler-1.15.4/lib/bundler/cli/exec.rb:27:in `run'
/usr/local/share/gems/gems/bundler-1.15.4/lib/bundler/cli.rb:362:in `exec'
/usr/local/share/gems/gems/bundler-1.15.4/lib/bundler/vendor/thor/lib/thor/command.rb:27:in `run'
/usr/local/share/gems/gems/bundler-1.15.4/lib/bundler/vendor/thor/lib/thor/invocation.rb:126:in `invoke_command'
/usr/local/share/gems/gems/bundler-1.15.4/lib/bundler/vendor/thor/lib/thor.rb:387:in `dispatch'
/usr/local/share/gems/gems/bundler-1.15.4/lib/bundler/cli.rb:22:in `dispatch'
/usr/local/share/gems/gems/bundler-1.15.4/lib/bundler/vendor/thor/lib/thor/base.rb:466:in `start'
/usr/local/share/gems/gems/bundler-1.15.4/lib/bundler/cli.rb:13:in `start'
/usr/local/share/gems/gems/bundler-1.15.4/exe/bundle:30:in `block in <top (required)>'
/usr/local/share/gems/gems/bundler-1.15.4/lib/bundler/friendly_errors.rb:121:in `with_friendly_errors'
/usr/local/share/gems/gems/bundler-1.15.4/exe/bundle:22:in `<top (required)>'
/usr/local/bin/bundle:23:in `load'
/usr/local/bin/bundle:23:in `<main>'
Thanks in Advance
Resolved by adding a Gemfile.local inside redmine directory
# Gemfile.local
gem 'multi_json'
gem 'json'
then run bundle lock --add-platform x86_64-linux (get your platform from ruby -v)
followed by bundle install --without development test
I'm just starting out with Rails and am following the Ruby on Rails essential training course and get problems trying to start WEBrick. Assuming it has something to do with my installation of mysql but not sure.
I made sure that I am in the correct directory (:C\sites\simple_cms)
I ran 'bundle install' before running 'rails s'
I followed these guides to get the gem installed (second to last entry): https://github.com/brianmario/mysql2/issues/372
I have ruby 2.2.1p85, rails 4.2.1 and this rubygem: mysql2-0.3.18-x64-mingw32 installed
Would appreciate some help from y'all :)
Stack trace:
C:\Sites\simple_cms>rails s
C:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/mysql2-0.3.18-x64-mingw32/lib/mysql2/mysql2.rb:2:in `require': cannot load such file -- mysql2/2.2/mysql2 (LoadError)
from C:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/mysql2-0.3.18-x64-mingw32/lib/mysql2/mysql2.rb:2:in `<top (required)>'
from C:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/mysql2-0.3.18-x64-mingw32/lib/mysql2.rb:31:in `require'
from C:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/mysql2-0.3.18-x64-mingw32/lib/mysql2.rb:31:in `<top (required)>'
from C:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/bundler-1.9.2/lib/bundler/runtime.rb:76:in `require'
from C:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/bundler-1.9.2/lib/bundler/runtime.rb:76:in `block (2 levels) in require'
from C:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/bundler-1.9.2/lib/bundler/runtime.rb:72:in `each'
from C:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/bundler-1.9.2/lib/bundler/runtime.rb:72:in `block in require'
from C:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/bundler-1.9.2/lib/bundler/runtime.rb:61:in `each'
from C:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/bundler-1.9.2/lib/bundler/runtime.rb:61:in `require'
from C:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/bundler-1.9.2/lib/bundler.rb:134:in `require'
from C:/Sites/simple_cms/config/application.rb:7:in `<top (required)>'
from C:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/railties-4.2.1/lib/rails/commands/commands_tasks.rb:78:in `require'
from C:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/railties-4.2.1/lib/rails/commands/commands_tasks.rb:78:in `block in server'
from C:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/railties-4.2.1/lib/rails/commands/commands_tasks.rb:75:in `tap'
from C:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/railties-4.2.1/lib/rails/commands/commands_tasks.rb:75:in `server'
from C:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/railties-4.2.1/lib/rails/commands/commands_tasks.rb:39:in `run_command!'
from C:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/railties-4.2.1/lib/rails/commands.rb:17:in `<top (required)>'
from bin/rails:4:in `require'
from bin/rails:4:in `<main>'
Today i installed ruby and rails gems everthing got success
but after when i tried to start server using command rails server i get some error it is being listed below please help me
C:\Ruby200-x64\project>rails server
C:/Ruby200-x64/lib/ruby/gems/2.0.0/gems/mysql2-0.3.13/lib/mysql2.rb:8:in `requir
e': 193: %1 is not a valid Win32 application. - C:/Ruby200-x64/lib/ruby/gems/2
.0.0/gems/mysql2-0.3.13/lib/mysql2/mysql2.so (LoadError)
from C:/Ruby200-x64/lib/ruby/gems/2.0.0/gems/mysql2-0.3.13/lib/mysql2.rb
:8:in `<top (required)>'
from C:/Ruby200-x64/lib/ruby/gems/2.0.0/gems/bundler-1.3.5/lib/bundler/r
untime.rb:72:in `require'
from C:/Ruby200-x64/lib/ruby/gems/2.0.0/gems/bundler-1.3.5/lib/bundler/r
untime.rb:72:in `block (2 levels) in require'
from C:/Ruby200-x64/lib/ruby/gems/2.0.0/gems/bundler-1.3.5/lib/bundler/r
untime.rb:70:in `each'
from C:/Ruby200-x64/lib/ruby/gems/2.0.0/gems/bundler-1.3.5/lib/bundler/r
untime.rb:70:in `block in require'
from C:/Ruby200-x64/lib/ruby/gems/2.0.0/gems/bundler-1.3.5/lib/bundler/r
untime.rb:59:in `each'
from C:/Ruby200-x64/lib/ruby/gems/2.0.0/gems/bundler-1.3.5/lib/bundler/r
untime.rb:59:in `require'
from C:/Ruby200-x64/lib/ruby/gems/2.0.0/gems/bundler-1.3.5/lib/bundler.r
b:132:in `require'
from C:/Ruby200-x64/project/config/application.rb:7:in `<top (required)>
'
from C:/Ruby200-x64/lib/ruby/gems/2.0.0/gems/railties-4.0.0/lib/rails/co
mmands.rb:76:in `require'
from C:/Ruby200-x64/lib/ruby/gems/2.0.0/gems/railties-4.0.0/lib/rails/co
mmands.rb:76:in `block in <top (required)>'
from C:/Ruby200-x64/lib/ruby/gems/2.0.0/gems/railties-4.0.0/lib/rails/co
mmands.rb:73:in `tap'
from C:/Ruby200-x64/lib/ruby/gems/2.0.0/gems/railties-4.0.0/lib/rails/co
mmands.rb:73:in `<top (required)>'
from bin/rails:4:in `require'
from bin/rails:4:in `<main>'
Try to execute
rake db:create
command to create database and paste the errors if any. There we can find meaningful error message
I'm trying to install Redmine on my fedora machine and I have been following the official wiki to install it, I have gotten up to step 5 when I am asked to run the
*rake generate_secret_token*
command, however when I do I get this error
rake aborted!
cannot load such file -- mysql2/mysql2
/home/usera/redmine-2.3/config/application.rb:7:in `<top (required)>'
/home/usera/redmine-2.3/Rakefile:5:in `<top (required)>'
(See full trace by running task with --trace)
with --trace
rake aborted!
cannot load such file -- mysql2/mysql2
/usr/local/share/gems/gems/mysql2-0.3.13/lib/mysql2.rb:8:in `require'
/usr/local/share/gems/gems/mysql2-0.3.13/lib/mysql2.rb:8:in `<top (required)>'
/usr/local/share/gems/gems/bundler-1.3.5/lib/bundler/runtime.rb:72:in `require'
/usr/local/share/gems/gems/bundler-1.3.5/lib/bundler/runtime.rb:72:in `block (2 levels) in require'
/usr/local/share/gems/gems/bundler-1.3.5/lib/bundler/runtime.rb:70:in `each'
/usr/local/share/gems/gems/bundler-1.3.5/lib/bundler/runtime.rb:70:in `block in require'
/usr/local/share/gems/gems/bundler-1.3.5/lib/bundler/runtime.rb:59:in `each'
/usr/local/share/gems/gems/bundler-1.3.5/lib/bundler/runtime.rb:59:in `require'
/usr/local/share/gems/gems/bundler-1.3.5/lib/bundler.rb:132:in `require'
/home/usera/redmine-2.3/config/application.rb:7:in `<top (required)>'
/usr/share/rubygems/rubygems/custom_require.rb:36:in `require'
/usr/share/rubygems/rubygems/custom_require.rb:36:in `require'
/home/usera/redmine-2.3/Rakefile:5:in `<top (required)>'
/usr/local/share/gems/gems/rake-10.1.0/lib/rake/rake_module.rb:25:in `load'
/usr/local/share/gems/gems/rake-10.1.0/lib/rake/rake_module.rb:25:in `load_rakefile'
/usr/local/share/gems/gems/rake-10.1.0/lib/rake/application.rb:637:in `raw_load_rakefile'
/usr/local/share/gems/gems/rake-10.1.0/lib/rake/application.rb:94:in `block in load_rakefile'
/usr/local/share/gems/gems/rake-10.1.0/lib/rake/application.rb:165:in `standard_exception_handling'
/usr/local/share/gems/gems/rake-10.1.0/lib/rake/application.rb:93:in `load_rakefile'
/usr/local/share/gems/gems/rake-10.1.0/lib/rake/application.rb:77:in `block in run'
/usr/local/share/gems/gems/rake-10.1.0/lib/rake/application.rb:165:in `standard_exception_handling'
/usr/local/share/gems/gems/rake-10.1.0/lib/rake/application.rb:75:in `run'
/usr/local/share/gems/gems/rake-10.1.0/bin/rake:33:in `<top (required)>'
/bin/rake:23:in `load'
/bin/rake:23:in `<main>'
I am running the command as root. This is the guide I used http://www.redmine.org/projects/redmine/wiki/RedmineInstall
Do you have installed the necessary native libraries for mysql2 adaptor ?
You can check:
mysql2 adapter issues in installing Redmine on Fedora 17
I copy LIMMYSQL.dll from MySql and put it in Ruby bin folder and then start rails server and I am getting below error. Please help me
c:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/activesupport-3.2.9/lib/active_support/dependencies.rb:251:in `require': 193: %1 is not a valid Win32
application. - c:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/mysql2-0.3.11-x86-mingw32/lib/mysql2/1.9/mysql2.so (LoadError)
from c:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/activesupport-3.2.9/lib/active_support/dependencies.rb:251:in `block in require'
from c:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/activesupport-3.2.9/lib/active_support/dependencies.rb:236:in `load_dependency'
from c:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/activesupport-3.2.9/lib/active_support/dependencies.rb:251:in `require'
from c:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/mysql2-0.3.11-x86-mingw32/lib/mysql2/mysql2.rb:2:in `<top (required)>'
from c:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/activesupport-3.2.9/lib/active_support/dependencies.rb:251:in `require'
from c:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/activesupport-3.2.9/lib/active_support/dependencies.rb:251:in `block in require'
from c:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/activesupport-3.2.9/lib/active_support/dependencies.rb:236:in `load_dependency'
from c:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/activesupport-3.2.9/lib/active_support/dependencies.rb:251:in `require'
from c:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/mysql2-0.3.11-x86-mingw32/lib/mysql2.rb:9:in `<top (required)>'
from c:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/bundler-1.0.22/lib/bundler/runtime.rb:68:in `require'
from c:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/bundler-1.0.22/lib/bundler/runtime.rb:68:in `block (2 levels) in require'
from c:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/bundler-1.0.22/lib/bundler/runtime.rb:66:in `each'
from c:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/bundler-1.0.22/lib/bundler/runtime.rb:66:in `block in require'
from c:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/bundler-1.0.22/lib/bundler/runtime.rb:55:in `each'
from c:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/bundler-1.0.22/lib/bundler/runtime.rb:55:in `require'
from c:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/bundler-1.0.22/lib/bundler.rb:122:in `require'
from d:/merlin_demo_app/demo_app/config/application.rb:7:in `<top (required)>'
from c:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/railties-3.2.9/lib/rails/commands.rb:53:in `require'
from c:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/railties-3.2.9/lib/rails/commands.rb:53:in `block in <top (required)>'
from c:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/railties-3.2.9/lib/rails/commands.rb:50:in `tap'
from c:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/railties-3.2.9/lib/rails/commands.rb:50:in `<top (required)>'
from script/rails:6:in `require'
from script/rails:6:in `<main>'
I have solved this, eventually!
I re-installed Ruby and Rails under RVM. I'm using Ruby version 1.9.2-p136.
After re-installing under rvm, this error was still present.
In the end the magic command that solved it was: