www/redmine is not working after upgrade

[Miroslav Lachman]

I already filed a PR for this problem:
https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=201112

Redmine is not able to start after upgrade. As I am not skilled Ruby 
person, I really don't know what the problem is and how can it be solved.

If I tried to run it on commandline, I got this trace message:

# /usr/local/bin/thin -D -c /usr/local/www/redmine -u www -g www -a 
0.0.0.0 -p 8080 -e production start
Changing process privilege to www:www
Using rack adapter
/usr/local/lib/ruby/gems/2.1/gems/bundler-1.10.4/lib/bundler/runtime.rb:34:in 
`block in setup': You have already activated rack 1.6.4, but your 
Gemfile requires rack 1.4.7. Prepending `bundle exec` to your command 
may solve this. (Gem::LoadError)
         from 
/usr/local/lib/ruby/gems/2.1/gems/bundler-1.10.4/lib/bundler/runtime.rb:19:in 
`setup'
         from 
/usr/local/lib/ruby/gems/2.1/gems/bundler-1.10.4/lib/bundler.rb:127:in 
`setup'
         from 
/usr/local/lib/ruby/gems/2.1/gems/bundler-1.10.4/lib/bundler/setup.rb:8:in 
`<top (required)>'
         from 
/usr/local/lib/ruby/site_ruby/2.1/rubygems/core_ext/kernel_require.rb:128:in 
`require'
         from 
/usr/local/lib/ruby/site_ruby/2.1/rubygems/core_ext/kernel_require.rb:128:in 
`rescue in require'
         from 
/usr/local/lib/ruby/site_ruby/2.1/rubygems/core_ext/kernel_require.rb:39:in 
`require'
         from /usr/local/www/redmine/config/boot.rb:6:in `<top (required)>'
         from 
/usr/local/lib/ruby/site_ruby/2.1/rubygems/core_ext/kernel_require.rb:54:in 
`require'
         from 
/usr/local/lib/ruby/site_ruby/2.1/rubygems/core_ext/kernel_require.rb:54:in 
`require'
         from /usr/local/www/redmine/config/application.rb:1:in `<top 
(required)>'
         from 
/usr/local/lib/ruby/site_ruby/2.1/rubygems/core_ext/kernel_require.rb:54:in 
`require'
         from 
/usr/local/lib/ruby/site_ruby/2.1/rubygems/core_ext/kernel_require.rb:54:in 
`require'
         from /usr/local/www/redmine/config/environment.rb:2:in `<top 
(required)>'
         from 
/usr/local/lib/ruby/site_ruby/2.1/rubygems/core_ext/kernel_require.rb:54:in 
`require'
         from 
/usr/local/lib/ruby/site_ruby/2.1/rubygems/core_ext/kernel_require.rb:54:in 
`require'
         from /usr/local/www/redmine/config.ru:3:in `block in <main>'
         from 
/usr/local/lib/ruby/gems/2.1/gems/rack-1.6.4/lib/rack/builder.rb:55:in 
`instance_eval'
         from 
/usr/local/lib/ruby/gems/2.1/gems/rack-1.6.4/lib/rack/builder.rb:55:in 
`initialize'
         from /usr/local/www/redmine/config.ru:1:in `new'
         from /usr/local/www/redmine/config.ru:1:in `<main>'
         from 
/usr/local/lib/ruby/gems/2.1/gems/thin-1.6.3/lib/rack/adapter/loader.rb:33:in 
`eval'
         from 
/usr/local/lib/ruby/gems/2.1/gems/thin-1.6.3/lib/rack/adapter/loader.rb:33:in 
`load'
         from 
/usr/local/lib/ruby/gems/2.1/gems/thin-1.6.3/lib/rack/adapter/loader.rb:42:in 
`for'
         from 
/usr/local/lib/ruby/gems/2.1/gems/thin-1.6.3/lib/thin/controllers/controller.rb:170:in 
`load_adapter'
         from 
/usr/local/lib/ruby/gems/2.1/gems/thin-1.6.3/lib/thin/controllers/controller.rb:74:in 
`start'
         from 
/usr/local/lib/ruby/gems/2.1/gems/thin-1.6.3/lib/thin/runner.rb:200:in 
`run_command'
         from 
/usr/local/lib/ruby/gems/2.1/gems/thin-1.6.3/lib/thin/runner.rb:156:in 
`run!'
         from /usr/local/lib/ruby/gems/2.1/gems/thin-1.6.3/bin/thin:6:in 
`<top (required)>'
         from /usr/local/bin/thin:23:in `load'
         from /usr/local/bin/thin:23:in `<main>'


Does anybody know some quick fix / workaround for this issue?

Miroslav Lachman