merb cannot load dm-mysql-adapter

Question

Would you help me on this issue?

gem list shows that dm-mysql-adapter has been installed, but merb cannot load it. I just want to start a simple merb application generated by merb-gen.

Loading init file from ./config/init.rb
Loading ./config/environments/development.rb
/usr/lib/ruby/gems/1.8/gems/dm-core-1.2.0/lib/dm-core/adapters.rb:163:in `require': no such file to load -- dm-mysql-adapter (LoadError)
    from /usr/lib/ruby/gems/1.8/gems/dm-core-1.2.0/lib/dm-core/adapters.rb:163:in `load_adapter'
    from /usr/lib/ruby/gems/1.8/gems/dm-core-1.2.0/lib/dm-core/adapters.rb:133:in `adapter_class'
    from /usr/lib/ruby/gems/1.8/gems/dm-core-1.2.0/lib/dm-core/adapters.rb:13:in `new'
    from /usr/lib/ruby/gems/1.8/gems/dm-core-1.2.0/lib/dm-core.rb:230:in `setup'
    from /home/pl/merb/merb-f/config/environments/development.rb:18
    from /usr/lib/ruby/gems/1.8/gems/merb-core-1.1.3/lib/merb-core/bootloader.rb:498:in `load'
    from /usr/lib/ruby/gems/1.8/gems/merb-core-1.1.3/lib/merb-core/bootloader.rb:498:in `load_env_config'
    from /usr/lib/ruby/gems/1.8/gems/merb-core-1.1.3/lib/merb-core/bootloader.rb:378:in `run'
    from /usr/lib/ruby/gems/1.8/gems/merb-core-1.1.3/lib/merb-core/bootloader.rb:97:in `run'
    from /usr/lib/ruby/gems/1.8/gems/merb-core-1.1.3/lib/merb-core/server.rb:172:in `bootup'
    from /usr/lib/ruby/gems/1.8/gems/merb-core-1.1.3/lib/merb-core/server.rb:42:in `start'
    from /usr/lib/ruby/gems/1.8/gems/merb-core-1.1.3/lib/merb-core.rb:165:in `start'
    from /usr/lib/ruby/gems/1.8/gems/merb-core-1.1.3/bin/merb:20
    from /usr/local/bin/merb:19:in `load'
    from /usr/local/bin/merb:19

me@server:~/merb/merb-f$ sudo gem list | grep "dm-mysql-adapter"
dm-mysql-adapter (1.2.0)

Answer 1

Root cause: Some database adapter misconfiguration. May be brought by Merb application generation, or manually editing.

Change database adapter from mysql to sqlite, it works.

Answer 2

Make sure Merb knows about your GEM_PATH.