Redmine

Addition. The most successfull attempt was tar-ing /var/www/rails_app dir on old (0.8.4) site, dumping database, then untar-ing in on /var/www/redmine.old on new site, restoring database. Then I downloaded latest redmine (1.2.1), untared it in /var/www/redmine, copied config/{email,database}.yml from old, copied files dir from old to new.
Then I ran rake config/initializers/session_store.rb and rake generate_session_store.
Next step must be rake db:migrate RAILS_ENV=production, but it fails:

# rake db:migrate RAILS_ENV=production
NOTE: SourceIndex.new(hash) is deprecated; From /var/www/redmine/config/../vendor/rails/railties/lib/rails/vendor_gem_source_index.rb:100:in `new'.
rake/rdoctask is deprecated.  Use rdoc/task instead (in RDoc 2.4.2+)
WARNING: 'task :t, arg, :needs => [deps]' is deprecated.  Please use 'task :t, [args] => [deps]' instead.
    at /var/www/redmine/lib/tasks/email.rake:170
==  AddCustomFieldsEditable: migrating ========================================
-- add_column(:custom_fields, :editable, :boolean, {:default=>true})
   -> 0.1325s
==  AddCustomFieldsEditable: migrated (0.1327s) ===============================

==  SetCustomFieldsEditable: migrating ========================================
==  SetCustomFieldsEditable: migrated (0.0155s) ===============================

==  AddProjectsLftAndRgt: migrating ===========================================
-- add_column(:projects, :lft, :integer)
   -> 0.0994s
-- add_column(:projects, :rgt, :integer)
   -> 0.0999s
==  AddProjectsLftAndRgt: migrated (0.1995s) ==================================

==  BuildProjectsTree: migrating ==============================================
rake aborted!
An error has occurred, all later migrations canceled:

Validation failed: repository is invalid

Tasks: TOP => db:migrate
(See full trace by running task with --trace)

How can I fix it? May be there is another way to upgrade?

Howdy,
It looks like this line "Validation failed: repository is invalid" is referring to the repository module (as in SVN, GIT, etc). The file that's throwing it is probably ./app/models/repository.rb

I had the same issue and solved it by deleting everything from the "repositories" table in the database: truncate repositories; (needless to say, be sure you have a backup of the database before doing this)

After you upgrade, you can go in and re-add the repositories to the projects manually.