active_adminのassets precompileがこけた

rails4 active_admin assets sass-rails

production環境でprecompileしようとしてこけた。

bundle exec rake assets:precompile RAILS_ENV=production
rake aborted!
NoMethodError: undefined method `environment' for nil:NilClass
  (in /home/m__z/public_html/railsapp/spree/app/assets/stylesheets/active_admin.css.scss)
/home/m__z/public_html/railsapp/spree/vendor/bundle/ruby/1.9.1/gems/sass-rails-4.0.1/lib/sass/rails/importer.rb:84:in `evaluate'
/home/m__z/public_html/railsapp/spree/vendor/bundle/ruby/1.9.1/gems/sass-rails-4.0.1/lib/sass/rails/importer.rb:70:in `engine_from_path'
/home/m__z/public_html/railsapp/spree/vendor/bundle/ruby/1.9.1/gems/sass-rails-4.0.1/lib/sass/rails/importer.rb:35:in `find'
/home/m__z/public_html/railsapp/spree/vendor/bundle/ruby/1.9.1/gems/sass-3.2.14/lib/sass/tree/import_node.rb:54:in `block in import'
/home/m__z/public_html/railsapp/spree/vendor/bundle/ruby/1.9.1/gems/sass-3.2.14/lib/sass/tree/import_node.rb:53:in `each'
/home/m__z/public_html/railsapp/spree/vendor/bundle/ruby/1.9.1/gems/sass-3.2.14/lib/sass/tree/import_node.rb:53:in `import'
/home/m__z/public_html/railsapp/spree/vendor/bundle/ruby/1.9.1/gems/sass-3.2.14/lib/sass/tree/import_node.rb:28:in `imported_file'
/home/m__z/public_html/railsapp/spree/vendor/bundle/ruby/1.9.1/gems/sass-3.2.14/lib/sass/tree/import_node.rb:37:in `css_import?'
/home/m__z/public_html/railsapp/spree/vendor/bundle/ruby/1.9.1/gems/sass-3.2.14/lib/sass/tree/visitors/perform.rb:217:in `visit_import'
/home/m__z/public_html/railsapp/spree/vendor/bundle/ruby/1.9.1/gems/sass-3.2.14/lib/sass/tree/visitors/base.rb:37:in `visit'
/home/m__z/public_html/railsapp/spree/vendor/bundle/ruby/1.9.1/gems/sass-3.2.14/lib/sass/tree/visitors/perform.rb:100:in `visit'
/home/m__z/public_html/railsapp/spree/vendor/bundle/ruby/1.9.1/gems/sass-3.2.14/lib/sass/tree/visitors/base.rb:53:in `block in visit_children'
/home/m__z/public_html/railsapp/spree/vendor/bundle/ruby/1.9.1/gems/sass-3.2.14/lib/sass/tree/visitors/base.rb:53:in `map'
/home/m__z/public_html/railsapp/spree/vendor/bundle/ruby/1.9.1/gems/sass-3.2.14/lib/sass/tree/visitors/base.rb:53:in `visit_children'
/home/m__z/public_html/railsapp/spree/vendor/bundle/ruby/1.9.1/gems/sass-3.2.14/lib/sass/tree/visitors/perform.rb:109:in `block in visit_children'
/home/m__z/public_html/railsapp/spree/vendor/bundle/ruby/1.9.1/gems/sass-3.2.14/lib/sass/tree/visitors/perform.rb:121:in `with_environment'
/home/m__z/public_html/railsapp/spree/vendor/bundle/ruby/1.9.1/gems/sass-3.2.14/lib/sass/tree/visitors/perform.rb:108:in `visit_children'
/home/m__z/public_html/railsapp/spree/vendor/bundle/ruby/1.9.1/gems/sass-3.2.14/lib/sass/tree/visitors/base.rb:37:in `block in visit'
/home/m__z/public_html/railsapp/spree/vendor/bundle/ruby/1.9.1/gems/sass-3.2.14/lib/sass/tree/visitors/perform.rb:128:in `visit_root'
/home/m__z/public_html/railsapp/spree/vendor/bundle/ruby/1.9.1/gems/sass-3.2.14/lib/sass/tree/visitors/base.rb:37:in `visit'
/home/m__z/public_html/railsapp/spree/vendor/bundle/ruby/1.9.1/gems/sass-3.2.14/lib/sass/tree/visitors/perform.rb:100:in `visit'
/home/m__z/public_html/railsapp/spree/vendor/bundle/ruby/1.9.1/gems/sass-3.2.14/lib/sass/tree/visitors/perform.rb:7:in `visit'
/home/m__z/public_html/railsapp/spree/vendor/bundle/ruby/1.9.1/gems/sass-3.2.14/lib/sass/tree/root_node.rb:20:in `render'
/home/m__z/public_html/railsapp/spree/vendor/bundle/ruby/1.9.1/gems/sass-3.2.14/lib/sass/engine.rb:315:in `_render'
/home/m__z/public_html/railsapp/spree/vendor/bundle/ruby/1.9.1/gems/sass-3.2.14/lib/sass/engine.rb:262:in `render'
/home/m__z/public_html/railsapp/spree/vendor/bundle/ruby/1.9.1/gems/sprockets-2.12.1/lib/sprockets/sass_template.rb:53:in `evaluate'
/home/m__z/public_html/railsapp/spree/vendor/bundle/ruby/1.9.1/gems/tilt-1.4.1/lib/tilt/template.rb:103:in `render'
/home/m__z/public_html/railsapp/spree/vendor/bundle/ruby/1.9.1/gems/sprockets-2.12.1/lib/sprockets/context.rb:197:in `block in evaluate'
/home/m__z/public_html/railsapp/spree/vendor/bundle/ruby/1.9.1/gems/sprockets-2.12.1/lib/sprockets/context.rb:194:in `each'
/home/m__z/public_html/railsapp/spree/vendor/bundle/ruby/1.9.1/gems/sprockets-2.12.1/lib/sprockets/context.rb:194:in `evaluate'
/home/m__z/public_html/railsapp/spree/vendor/bundle/ruby/1.9.1/gems/sprockets-2.12.1/lib/sprockets/processed_asset.rb:12:in `initialize'
/home/m__z/public_html/railsapp/spree/vendor/bundle/ruby/1.9.1/gems/sprockets-2.12.1/lib/sprockets/base.rb:374:in `new'
/home/m__z/public_html/railsapp/spree/vendor/bundle/ruby/1.9.1/gems/sprockets-2.12.1/lib/sprockets/base.rb:374:in `block in build_asset'
/home/m__z/public_html/railsapp/spree/vendor/bundle/ruby/1.9.1/gems/sprockets-2.12.1/lib/sprockets/base.rb:395:in `circular_call_protection'
/home/m__z/public_html/railsapp/spree/vendor/bundle/ruby/1.9.1/gems/sprockets-2.12.1/lib/sprockets/base.rb:373:in `build_asset'
/home/m__z/public_html/railsapp/spree/vendor/bundle/ruby/1.9.1/gems/sprockets-2.12.1/lib/sprockets/index.rb:94:in `block in build_asset'
/home/m__z/public_html/railsapp/spree/vendor/bundle/ruby/1.9.1/gems/sprockets-2.12.1/lib/sprockets/caching.rb:58:in `cache_asset'
/home/m__z/public_html/railsapp/spree/vendor/bundle/ruby/1.9.1/gems/sprockets-2.12.1/lib/sprockets/index.rb:93:in `build_asset'
/home/m__z/public_html/railsapp/spree/vendor/bundle/ruby/1.9.1/gems/sprockets-2.12.1/lib/sprockets/base.rb:287:in `find_asset'
/home/m__z/public_html/railsapp/spree/vendor/bundle/ruby/1.9.1/gems/sprockets-2.12.1/lib/sprockets/index.rb:61:in `find_asset'
/home/m__z/public_html/railsapp/spree/vendor/bundle/ruby/1.9.1/gems/sprockets-2.12.1/lib/sprockets/bundled_asset.rb:16:in `initialize'
/home/m__z/public_html/railsapp/spree/vendor/bundle/ruby/1.9.1/gems/sprockets-2.12.1/lib/sprockets/base.rb:377:in `new'
/home/m__z/public_html/railsapp/spree/vendor/bundle/ruby/1.9.1/gems/sprockets-2.12.1/lib/sprockets/base.rb:377:in `build_asset'
/home/m__z/public_html/railsapp/spree/vendor/bundle/ruby/1.9.1/gems/sprockets-2.12.1/lib/sprockets/index.rb:94:in `block in build_asset'
/home/m__z/public_html/railsapp/spree/vendor/bundle/ruby/1.9.1/gems/sprockets-2.12.1/lib/sprockets/caching.rb:58:in `cache_asset'
/home/m__z/public_html/railsapp/spree/vendor/bundle/ruby/1.9.1/gems/sprockets-2.12.1/lib/sprockets/index.rb:93:in `build_asset'
/home/m__z/public_html/railsapp/spree/vendor/bundle/ruby/1.9.1/gems/sprockets-2.12.1/lib/sprockets/base.rb:287:in `find_asset'
/home/m__z/public_html/railsapp/spree/vendor/bundle/ruby/1.9.1/gems/sprockets-2.12.1/lib/sprockets/index.rb:61:in `find_asset'
/home/m__z/public_html/railsapp/spree/vendor/bundle/ruby/1.9.1/gems/sprockets-2.12.1/lib/sprockets/manifest.rb:211:in `block in find_asset'
/home/m__z/public_html/railsapp/spree/vendor/bundle/ruby/1.9.1/gems/sprockets-2.12.1/lib/sprockets/manifest.rb:257:in `benchmark'
/home/m__z/public_html/railsapp/spree/vendor/bundle/ruby/1.9.1/gems/sprockets-2.12.1/lib/sprockets/manifest.rb:210:in `find_asset'
/home/m__z/public_html/railsapp/spree/vendor/bundle/ruby/1.9.1/gems/sprockets-2.12.1/lib/sprockets/manifest.rb:119:in `block in compile'
/home/m__z/public_html/railsapp/spree/vendor/bundle/ruby/1.9.1/gems/sprockets-2.12.1/lib/sprockets/manifest.rb:118:in `each'
/home/m__z/public_html/railsapp/spree/vendor/bundle/ruby/1.9.1/gems/sprockets-2.12.1/lib/sprockets/manifest.rb:118:in `compile'
/home/m__z/public_html/railsapp/spree/vendor/bundle/ruby/1.9.1/gems/sprockets-rails-2.0.1/lib/sprockets/rails/task.rb:60:in `block (3 levels) in define'
/home/m__z/public_html/railsapp/spree/vendor/bundle/ruby/1.9.1/gems/sprockets-2.12.1/lib/rake/sprocketstask.rb:146:in `with_logger'
/home/m__z/public_html/railsapp/spree/vendor/bundle/ruby/1.9.1/gems/sprockets-rails-2.0.1/lib/sprockets/rails/task.rb:59:in `block (2 levels) in define'
Tasks: TOP => assets:precompile
(See full trace by running task with --trace)

ためしにActiveAdminのcssとjsを削除するとSpreeのcssとjsで発生した。
結論として、ActiveAdminのせいではなく、sass-railsのバージョンを上げることで直った。

gem 'sass-rails', '~> 4.0.0'

これを以下に修正

gem 'sass-rails', '4.0.2'


参考リンク | undefined method `environment' for nil:NilClass #3005
https://github.com/gregbell/active_admin/issues/3005