我正在使用https://github.com/thuss/standalone-migrations在 cakephp 环境中执行数据库迁移。我最终试图在使用 post-checkout git hook 签出不同版本的代码后自动执行数据库迁移。
在 cli 上正常运行可以正常运行bundle exec rake db:migrate，rake db:migrate与其他任何命令一样。如果我把命令放进去，.git/hooks/post-checkout它会吐出一个错误，抱怨undefined class/module Encoding
git hook 命令是bundle exec rake db:migrate --trace.
平台：Mac OS X Lion 10.7.5
这是整个错误：
耙中止！ 未定义的类/模块编码 /Users/andy/.rvm/gems/ruby-1.9.3-p194/gems/json-1.7.5/lib/json/ext/parser.bundle /Users/andy/.rvm/gems/ruby-1.9.3-p194/gems/json-1.7.5/lib/json/ext.rb:13 /Users/andy/.rvm/gems/ruby-1.9.3-p194/gems/json-1.7.5/lib/json.rb:58:in `require' /Users/andy/.rvm/gems/ruby-1.9.3-p194/gems/json-1.7.5/lib/json.rb:58 /Users/andy/.rvm/gems/ruby-1.9.3-p194/gems/activesupport-3.2.8/lib/active_support/core_ext/object/to_json.rb:3:in `require' /Users/andy/.rvm/gems/ruby-1.9.3-p194/gems/activesupport-3.2.8/lib/active_support/core_ext/object/to_json.rb:3 /Users/andy/.rvm/gems/ruby-1.9.3-p194/gems/activesupport-3.2.8/lib/active_support/core_ext/object.rb:10:in `require' /Users/andy/.rvm/gems/ruby-1.9.3-p194/gems/activesupport-3.2.8/lib/active_support/core_ext/object.rb:10 /Users/andy/.rvm/gems/ruby-1.9.3-p194/gems/activesupport-3.2.8/lib/active_support/core_ext.rb:2:in `require' /Users/andy/.rvm/gems/ruby-1.9.3-p194/gems/activesupport-3.2.8/lib/active_support/core_ext.rb:2 /Users/andy/.rvm/gems/ruby-1.9.3-p194/gems/activesupport-3.2.8/lib/active_support/core_ext.rb:1:in `each' /Users/andy/.rvm/gems/ruby-1.9.3-p194/gems/activesupport-3.2.8/lib/active_support/core_ext.rb:1 /Users/andy/.rvm/gems/ruby-1.9.3-p194/gems/activesupport-3.2.8/lib/active_support/all.rb:3:in `require' /Users/andy/.rvm/gems/ruby-1.9.3-p194/gems/activesupport-3.2.8/lib/active_support/all.rb:3 /Users/andy/.rvm/gems/ruby-1.9.3-p194/gems/standalone_migrations-2.0.1/lib/standalone_migrations/configurator.rb:1:in `require' /Users/andy/.rvm/gems/ruby-1.9.3-p194/gems/standalone_migrations-2.0.1/lib/standalone_migrations/configurator.rb:1 /Users/andy/.rvm/gems/ruby-1.9.3-p194/gems/standalone_migrations-2.0.1/lib/standalone_migrations.rb:8:in `require' /Users/andy/.rvm/gems/ruby-1.9.3-p194/gems/standalone_migrations-2.0.1/lib/standalone_migrations.rb:8 /Users/andy/.rvm/gems/ruby-1.9.3-p194/gems/standalone_migrations-2.0.1/lib/tasks/standalone_migrations.rb:9:in `require' /Users/andy/.rvm/gems/ruby-1.9.3-p194/gems/standalone_migrations-2.0.1/lib/tasks/standalone_migrations.rb:9 /Users/andy/source/idio/cake/Rakefile:6:in `require' /Users/andy/source/idio/cake/Rakefile:6 /Users/andy/.rvm/gems/ruby-1.9.3-p194@global/gems/rake-0.9.2.2/lib/rake/rake_module.rb:25:in `load' /Users/andy/.rvm/gems/ruby-1.9.3-p194@global/gems/rake-0.9.2.2/lib/rake/rake_module.rb:25:in `load_rakefile' /Users/andy/.rvm/gems/ruby-1.9.3-p194@global/gems/rake-0.9.2.2/lib/rake/application.rb:501:in `raw_load_rakefile' /Users/andy/.rvm/gems/ruby-1.9.3-p194@global/gems/rake-0.9.2.2/lib/rake/application.rb:82:in `load_rakefile' /Users/andy/.rvm/gems/ruby-1.9.3-p194@global/gems/rake-0.9.2.2/lib/rake/application.rb:133:in `standard_exception_handling' /Users/andy/.rvm/gems/ruby-1.9.3-p194@global/gems/rake-0.9.2.2/lib/rake/application.rb:81:in `load_rakefile' /Users/andy/.rvm/gems/ruby-1.9.3-p194@global/gems/rake-0.9.2.2/lib/rake/application.rb:65:in `run' /Users/andy/.rvm/gems/ruby-1.9.3-p194@global/gems/rake-0.9.2.2/lib/rake/application.rb:133:in `standard_exception_handling' /Users/andy/.rvm/gems/ruby-1.9.3-p194@global/gems/rake-0.9.2.2/lib/rake/application.rb:63:in `run' /usr/bin/rake:31
我对红宝石不太感冒。我尝试了各种技巧，删除了所有的 gem，重新安装了等等。总是一样的。
谢谢。