config/dependency.rbの形式が変わったようなので、メモです。

ruby>>

dependencies are generated using a strict version, don't forget to edit the dependency versions when upgrading.

merb_gems_version = "1.0.8.1"
dm_gems_version = "0.9.9"
do_gems_version = "0.9.10.1"

For more information about each component, please read http://wiki.merbivore.com/faqs/merb_components

dependency "merb-core", merb_gems_version
dependency "merb-action-args", merb_gems_version
dependency "merb-assets", merb_gems_version
dependency("merb-cache", merb_gems_version) do
Merb::Cache.setup do
register(Merb::Cache::FileStore)
end
end
dependency "merb-helpers", merb_gems_version
dependency "merb-mailer", merb_gems_version
dependency "merb-slices", merb_gems_version
dependency "merb-auth-core", merb_gems_version
dependency "merb-auth-more", merb_gems_version
dependency "merb-auth-slice-password", merb_gems_version
dependency "merb-param-protection", merb_gems_version
dependency "merb-exceptions", merb_gems_version

dependency "data_objects", do_gems_version
dependency "do_sqlite3", do_gems_version # If using another database, replace this
dependency "dm-core", dm_gems_version
dependency "dm-aggregates", dm_gems_version
dependency "dm-migrations", dm_gems_version
dependency "dm-timestamps", dm_gems_version
dependency "dm-types", dm_gems_version
dependency "dm-validations", dm_gems_version
dependency "dm-serializer", dm_gems_version

dependency "merb_datamapper", merb_gems_version
<<--

merb_gems_version、
dm_gems_version、
do_gems_version の三つの系列のバージョンに分かれたのですね。