merb-more

I'm running the latest dm-core, dm-more, merb-core, and merb-more of trunk. When trying to generate a resource, I get this error:

$ merb-gen resource voucher
/Library/Ruby/Gems/1.8/gems/data_objects-0.9.0/lib/logger.rb:58: warning: already initialized constant LEVELS
/Library/Ruby/Gems/1.8/gems/data_objects-0.9.0/lib/logger.rb:197: warning: already initialized constant DeadLogger
/Library/Ruby/Gems/1.8/gems/activesupport-2.0.2/lib/active_support/clean_logger.rb:35: undefined method `datetime_format=' for class `Logger' (NameError)
	from /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ruby/1.8/rubygems/custom_require.rb:27:in `gem_original_require'
	from /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ruby/1.8/rubygems/custom_require.rb:27:in `require'
	from /Library/Ruby/Gems/1.8/gems/activesupport-2.0.2/lib/active_support.rb:32
	from /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ruby/1.8/rubygems/custom_require.rb:27:in `gem_original_require'
	from /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ruby/1.8/rubygems/custom_require.rb:27:in `require'
	from /Library/Ruby/Gems/1.8/gems/rubigen-1.3.1/lib/rubigen.rb:4
	from /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ruby/1.8/rubygems/custom_require.rb:27:in `gem_original_require'
	from /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ruby/1.8/rubygems/custom_require.rb:27:in `require'
	from /Library/Ruby/Gems/1.8/gems/merb-gen-0.9.3/bin/merb-gen:21
	from /Library/Ruby/Gems/1.8/gems/merb-gen-0.9.3/bin/merb-gen:19:in `each'
	from /Library/Ruby/Gems/1.8/gems/merb-gen-0.9.3/bin/merb-gen:19
	from /usr/bin/merb-gen:19:in `load'
	from /usr/bin/merb-gen:19

Any idea what the problem might be?