I just started to learn Merb and DataMapper.
I installed them with RubyGems, but it raised error because
Merb requires DataMapper 0.9.6 but officialy released only 0.9.5.
So I decided to install them from source, and found it is hard
to install them from source.
The following is the complete steps to install Merb and DataMapper
from source.
## install RubyGems 1.2.0 or later
$ tar xzf rubygems-1.2.0.tar.gz
$ cd rubygems-1.2.0/
$ sudo ruby setup.rb
## install dependencies of extlib
$ sudo gem install rake rspec english
## install extlib from source
## (both Merb and DataMapper depend on extlib)
$ git clone git://github.com/sam/extlib.git
$ (cd extlib; sudo rake install) # extlib-0.9.7
## install dependencies of Merb
$ sudo gem install erubis json_pure rack mime-types hpricot thor
$ sudo gem install ruby2ruby templater haml builder mailfactory mongrel
$ sudo gem install sequel
## install Merb from source
$ git clone git://github.com/wycats/merb-core.git
$ git clone git://github.com/wycats/merb-more.git
$ git clone git://github.com/wycats/merb-plugins.git
$ (cd merb-core; sudo rake install) # merb-core-0.9.8
$ (cd merb-more; sudo rake install) # merb-more-0.9.8
$ (cd merb-plugins; sudo rake install) # merb-xxxx-0.9.8
## install dependencies of DataObject and DataMapper
$ sudo gem install addressable
$ which mysql_config
/usr/local/mysql/bin/mysql_config
## install DataObject from source
$ git clone git://github.com/sam/do.git
$ (cd do/data_objects; sudo rake install) # data_objects-0.9.6
$ (cd do/do_mysql; sudo rake install) # do_mysql-0.9.6
## install DataMapper from source
$ git clone git://github.com/sam/dm-core.git
$ git clone git://github.com/sam/dm-more.git
$ (cd dm-core; sudo rake install) # dm-core-0.9.6
$ (cd dm-more; sudo rake install) # dm-more-0.9.6
After that, you can type ‘merb-gen app myapp’ and play with them.
I hope this helps beginners of Merb and DataMapper.