Redmine

I am trying to install Redmine 2 on Ubuntu 12.10 using the following repository: https://launchpad.net/~ondrej/+archive/redmine

After adding it to my sources.list I try to install redmine and redmine-sqlite, only to stumble upon the following:

Creating config file /etc/redmine/default/database.yml.new with new version
creating database redmine_default: already exists.
Invalid gemspec in [/usr/share/rubygems-integration/1.9.1/specifications/actionpack-3.2.8.gemspec]: Illformed requirement ["~> #<Gem::Version:0x558e7718>"]
Invalid gemspec in [/usr/share/rubygems-integration/1.9.1/specifications/actionpack-3.2.8.gemspec]: Illformed requirement ["~> #<Gem::Version:0x558e7718>"]
rake aborted!
No such file or directory - /etc/redmine/default/session.yml

(See full trace by running task with --trace)
dpkg: error processing redmine (--configure):
 subprocess installed post-installation script returned error exit status 1
Errors were encountered while processing:
 redmine
E: Sub-process /usr/bin/dpkg returned an error code (1)

If I do sudo rake generate_secret_token --trace in /usr/share/redmine I get:

Invalid gemspec in [/usr/share/rubygems-integration/1.9.1/specifications/actionpack-3.2.8.gemspec]: Illformed requirement ["~> #<Gem::Version:0x558e7718>"]
Invalid gemspec in [/usr/share/rubygems-integration/1.9.1/specifications/actionpack-3.2.8.gemspec]: Illformed requirement ["~> #<Gem::Version:0x558e7718>"]
rake aborted!
No such file or directory - /etc/redmine/default/session.yml
/usr/lib/ruby/1.9.1/psych.rb:297:in `initialize'
/usr/lib/ruby/1.9.1/psych.rb:297:in `open'
/usr/lib/ruby/1.9.1/psych.rb:297:in `load_file'
/usr/share/redmine/config/application.rb:70:in `<class:Application>'
/usr/share/redmine/config/application.rb:25:in `<module:RedmineApp>'
/usr/share/redmine/config/application.rb:24:in `<top (required)>'
/usr/lib/ruby/1.9.1/rubygems/custom_require.rb:36:in `require'
/usr/lib/ruby/1.9.1/rubygems/custom_require.rb:36:in `require'
/usr/share/redmine/Rakefile:5:in `<top (required)>'
/usr/lib/ruby/vendor_ruby/rake/rake_module.rb:25:in `load'
/usr/lib/ruby/vendor_ruby/rake/rake_module.rb:25:in `load_rakefile'
/usr/lib/ruby/vendor_ruby/rake/application.rb:501:in `raw_load_rakefile'
/usr/lib/ruby/vendor_ruby/rake/application.rb:82:in `block in load_rakefile'
/usr/lib/ruby/vendor_ruby/rake/application.rb:133:in `standard_exception_handling'
/usr/lib/ruby/vendor_ruby/rake/application.rb:81:in `load_rakefile'
/usr/lib/ruby/vendor_ruby/rake/application.rb:65:in `block in run'
/usr/lib/ruby/vendor_ruby/rake/application.rb:133:in `standard_exception_handling'
/usr/lib/ruby/vendor_ruby/rake/application.rb:63:in `run'
/usr/bin/rake:27:in `<main>'

What do I need to do to solve this problem?