What is causing private method `gsub` called for nil:NilClass during Rails migration?
root@beta:/vol/opt/dev/capistrano/foo-alpha/releases/20120330233010# RAILS_ENV=production rake db:migrate --trace
rake aborted!
private method `gsub' called for nil:NilClass
/usr/local/rvm/gems/jruby-1.6.6@global/gems/bundler-1.1.3/lib/bundler/runtime.rb:77:in `require'
org/jruby/RubyArray.java:1614:in `each'
/usr/local/rvm/gems/jruby-1.6.6@global/gems/bundler-1.1.3/lib/bundler/runtime.rb:55:in `require'
/usr/local/rvm/gems/jruby-1.6.6@global/gems/bundler-1.1.3/lib/bundler.rb:119:in `require'
/vol/opt/dev/capistrano/foo-alpha/releases/20120330233010/config/application.rb:7:in `(root)'
org/jruby/RubyKernel.java:1027:in `require'
/usr/local/rvm/rubies/jruby-1.6.6/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:36:in `require'
/vol/opt/dev/capistrano/foo-alpha/releases/20120330233010/config/application.rb:4:in `(root)'
org/jruby/RubyKernel.java:1052:in `load'
/vol/opt/dev/capistrano/foo-alpha/releases/20120330233010/Rakefile:25:in `load_rakefile'
/usr/local/rvm/gems/jruby-1.6.6@foo/gems/rake-0.9.2.2/lib/rake/application.rb:501:in `raw_load_rakefile'
/usr/local/rvm/gems/jruby-1.6.6@foo/gems/rake-0.9.2.2/lib/rake/application.rb:82:in `load_rakefile'
/usr/local/rvm/gems/jruby-1.6.6@foo/gems/rake-0.9.2.2/lib/rake/application.rb:133:in `standard_exception_handling'
/usr/local/rvm/gems/jruby-1.6.6@foo/gems/rake-0.9.2.2/lib/rake/application.rb:81:in `load_rakefile'
/usr/local/rvm/gems/jruby-1.6.6@foo/gems/rake-0.9.2.2/lib/rake/application.rb:65:in `run'
/usr/local/rvm/gems/jruby-1.6.6@foo/gems/rake-0.9.2.2/lib/rake/application.rb:133:in `standard_exception_handling'
/usr/local/rvm/gems/jruby-1.6.6@foo/gems/rake-0.9.2.2/lib/rake/application.rb:63:in `run'
/usr/local/rvm/gems/jruby-1.6.6@foo/gems/rake-0.9.2.2/bin/rake:33:in `(root)'
org/jruby/RubyKernel.java:1052:in `load'
/usr/local/rvm/gems/jruby-1.6.6@foo/bin/rake:19:in `(root)'

#<LoadError: no such file to load -- activerecord-jdbcmysql-adapter>

# gem list |grep -i activerecord-jdbcmysql-adapter
activerecord-jdbcmysql-adapter (1.2.2)

cd /vol/opt/dev/capistrano/foo-alpha/releases/20120330233010

RAILS_ENV=production bundle install

RAILS_ENV=production rails s

@definition.dependencies.each do |dep|
    # Skip the dependency if it is not in any of the requested groups
    next unless ((dep.groups & groups).any? && dep.current_platform?)