未定义的方法auto_upgrade！ 将Sinatra / DataMapper应用程序推送到Heroku时
有没有人知道在Heroku的Bamboo堆栈上运行使用DataMapper的Sinatra应用程序所需的神奇咒语？ Bamboo堆栈不包含任何预安装的系统gem，无论我尝试什么样的gem组合，我都会遇到此错误：
undefined method `auto_upgrade!' for DataMapper:Module (NoMethodError) 这就是我的.gems文件中的内容：
sinatra pg datamapper do_postgres dm-postgres-adapter
这些是我将应用程序推送到Heroku时安装的依赖项：
-----> Heroku receiving push -----> Sinatra app detected -----> Installing gem sinatra from http://rubygems.org Successfully installed sinatra-1.0 1 gem installed -----> Installing gem pg from http://rubygems.org Building native extensions. This could take a while... Successfully installed pg-0.9.0 1 gem installed -----> Installing gem datamapper from http://rubygems.org Successfully installed extlib-0.9.15 Successfully installed addressable-2.2.1 Successfully installed dm-core-1.0.2 Successfully installed dm-aggregates-1.0.2 Successfully installed dm-migrations-1.0.2 Successfully installed dm-constraints-1.0.2 Successfully installed dm-transactions-1.0.2 Successfully installed fastercsv-1.5.3 Successfully installed json_pure-1.4.6 Successfully installed dm-serializer-1.0.2 Successfully installed dm-timestamps-1.0.2 Successfully installed dm-validations-1.0.2 Successfully installed uuidtools-2.1.1 Successfully installed stringex-1.1.0 Successfully installed dm-types-1.0.2 Successfully installed datamapper-1.0.2 16 gems installed -----> Installing gem do_postgres from http://rubygems.org Building native extensions. This could take a while... Successfully installed data_objects-0.10.2 Successfully installed do_postgres-0.10.2 2 gems installed -----> Installing gem dm-postgres-adapter from http://rubygems.org Successfully installed dm-do-adapter-1.0.2 Successfully installed dm-postgres-adapter-1.0.2 2 gems installed
该应用程序使用SQLite3在本地工作正常。 我错过了另一个PostgreSQL组件吗？
dm-migrations gem添加了DataMapper.auto_upgrade！。 在自动升级之前，您是否需要dm-migrations或datamapper gem？