undefined method gem_dir' for nil:NilClass` in db:seed

[yottanami]

rake aborted!
NoMethodError: undefined method `gem_dir' for nil:NilClass
/home/yottanami/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/gems/model_discovery-0.3.8/lib/model_discovery/discovery.rb:13:in `block in build_table_list'
/home/yottanami/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/gems/model_discovery-0.3.8/lib/model_discovery/discovery.rb:9:in `each'
/home/yottanami/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/gems/model_discovery-0.3.8/lib/model_discovery/discovery.rb:9:in `build_table_list'
/home/yottanami/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/gems/model_discovery-0.3.8/db/seeds.rb:1:in `<top (required)>'
/home/yottanami/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/gems/activesupport-5.0.2/lib/active_support/dependencies.rb:287:in `load'
/home/yottanami/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/gems/activesupport-5.0.2/lib/active_support/dependencies.rb:287:in `block in load'
/home/yottanami/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/gems/activesupport-5.0.2/lib/active_support/dependencies.rb:259:in `load_dependency'
/home/yottanami/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/gems/activesupport-5.0.2/lib/active_support/dependencies.rb:287:in `load'
/home/yottanami/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/gems/railties-5.0.2/lib/rails/engine.rb:549:in `load_seed'
/home/yottanami/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/gems/railties-5.0.2/lib/rails/railtie.rb:193:in `public_send'
/home/yottanami/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/gems/railties-5.0.2/lib/rails/railtie.rb:193:in `method_missing'
/home/yottanami/src/Faalis/db/seeds.rb:2:in `<top (required)>'
/home/yottanami/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/gems/activesupport-5.0.2/lib/active_support/dependencies.rb:287:in `load'
/home/yottanami/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/gems/activesupport-5.0.2/lib/active_support/dependencies.rb:287:in `block in load'
/home/yottanami/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/gems/activesupport-5.0.2/lib/active_support/dependencies.rb:259:in `load_dependency'
/home/yottanami/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/gems/activesupport-5.0.2/lib/active_support/dependencies.rb:287:in `load'
/home/yottanami/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/gems/railties-5.0.2/lib/rails/engine.rb:549:in `load_seed'
/home/yottanami/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/gems/railties-5.0.2/lib/rails/railtie.rb:193:in `public_send'
/home/yottanami/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/gems/railties-5.0.2/lib/rails/railtie.rb:193:in `method_missing'
/home/yottanami/src/project/db/seeds.rb:1:in `<top (required)>'
/home/yottanami/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/gems/activesupport-5.0.2/lib/active_support/dependencies.rb:287:in `load'
/home/yottanami/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/gems/activesupport-5.0.2/lib/active_support/dependencies.rb:287:in `block in load'
/home/yottanami/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/gems/activesupport-5.0.2/lib/active_support/dependencies.rb:259:in `load_dependency'
/home/yottanami/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/gems/activesupport-5.0.2/lib/active_support/dependencies.rb:287:in `load'
/home/yottanami/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/gems/railties-5.0.2/lib/rails/engine.rb:549:in `load_seed'
/home/yottanami/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/gems/activerecord-5.0.2/lib/active_record/tasks/database_tasks.rb:268:in `load_seed'
/home/yottanami/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/gems/activerecord-5.0.2/lib/active_record/railties/databases.rake:196:in `block (2 levels) in <top (required)>'
/home/yottanami/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/gems/rake-12.0.0/lib/rake/task.rb:250:in `call'
/home/yottanami/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/gems/rake-12.0.0/lib/rake/task.rb:250:in `block in execute'
/home/yottanami/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/gems/rake-12.0.0/lib/rake/task.rb:250:in `each'
/home/yottanami/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/gems/rake-12.0.0/lib/rake/task.rb:250:in `execute'
/home/yottanami/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/gems/rake-12.0.0/lib/rake/task.rb:194:in `block in invoke_with_call_chain'
/home/yottanami/.rbenv/versions/2.2.3/lib/ruby/2.2.0/monitor.rb:211:in `mon_synchronize'
/home/yottanami/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/gems/rake-12.0.0/lib/rake/task.rb:187:in `invoke_with_call_chain'
/home/yottanami/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/gems/rake-12.0.0/lib/rake/task.rb:180:in `invoke'
/home/yottanami/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/gems/rake-12.0.0/lib/rake/application.rb:152:in `invoke_task'
/home/yottanami/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/gems/rake-12.0.0/lib/rake/application.rb:108:in `block (2 levels) in top_level'
/home/yottanami/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/gems/rake-12.0.0/lib/rake/application.rb:108:in `each'
/home/yottanami/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/gems/rake-12.0.0/lib/rake/application.rb:108:in `block in top_level'
/home/yottanami/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/gems/rake-12.0.0/lib/rake/application.rb:117:in `run_with_threads'
/home/yottanami/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/gems/rake-12.0.0/lib/rake/application.rb:102:in `top_level'
/home/yottanami/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/gems/rake-12.0.0/lib/rake/application.rb:80:in `block in run'
/home/yottanami/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/gems/rake-12.0.0/lib/rake/application.rb:178:in `standard_exception_handling'
/home/yottanami/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/gems/rake-12.0.0/lib/rake/application.rb:77:in `run'
/home/yottanami/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/gems/rake-12.0.0/exe/rake:27:in `<top (required)>'
/home/yottanami/.rbenv/versions/2.2.3/bin/rake:23:in `load'
/home/yottanami/.rbenv/versions/2.2.3/bin/rake:23:in `<main>'
Tasks: TOP => db:seed