私が実行すると：
$ heroku run bundle exec rake environment elasticsearch:import:model CLASS='Artist' FORCE=true
ターミナルでの応答は次のとおりです。
Running bundle exec rake environment elasticsearch:import:model CLASS=Artist FORCE=true on doremi... up, run.3015
Starting up a new ElasticSearch client with https://hexcode.bonsai.io
rake aborted!
NameError: uninitialized constant Elasticsearch
/app/vendor/bundle/ruby/2.0.0/gems/bonsai-elasticsearch-rails-0.0.4/lib/bonsai/elasticsearch/rails.rb:4:in `<top (required)>'
/app/vendor/bundle/ruby/2.0.0/gems/bundler-1.9.7/lib/bundler/runtime.rb:85:in `require'
/app/vendor/bundle/ruby/2.0.0/gems/bundler-1.9.7/lib/bundler/runtime.rb:85:in `rescue in block in require'
/app/vendor/bundle/ruby/2.0.0/gems/bundler-1.9.7/lib/bundler/runtime.rb:68:in `block in require'
/app/vendor/bundle/ruby/2.0.0/gems/bundler-1.9.7/lib/bundler/runtime.rb:61:in `each'
/app/vendor/bundle/ruby/2.0.0/gems/bundler-1.9.7/lib/bundler/runtime.rb:61:in `require'
/app/vendor/bundle/ruby/2.0.0/gems/bundler-1.9.7/lib/bundler.rb:134:in `require'
/app/config/application.rb:16:in `<top (required)>'
/app/Rakefile:4:in `require'
/app/Rakefile:4:in `<top (required)>'
(See full trace by running task with --trace)
エラーは、この require ステートメントから発生しているようですlib/tasks/elasticsearch.rake
require 'elasticsearch/rails/tasks/import'
すべてのelastic-*gem が最新バージョンであることを確認しました。elasticsearch-rails と elasticsearch-model の場合は 0.1.7、bonsai-elasticsearch-rails の場合は 0.0.4 ですが、ここで気づきましたhttps://rubygems.org/ gems/bonsai-elasticsearch-rails bonsai-elastic-search rails は bundler 1.5 に依存しており、Heroku は 1.9.7 を使用していますが、これは私が見る限り変更できません。これが問題の核心でしょうか？
デプロイしようとすると、ログにも同様のエラーが記録されます
Oct 09 17:04:27 doremi app/worker.1: NameError: uninitialized constant Elasticsearch
Oct 09 17:04:27 doremi app/worker.1: rake aborted!
Oct 09 17:04:27 doremi app/worker.1: /app/vendor/bundle/ruby/2.2.0/gems/bonsai-elasticsearch-rails-0.0.4/lib/bonsai/elasticsearch/rails.rb:4:in `<top (required)>'
Oct 09 17:04:27 doremi app/worker.1: /app/vendor/bundle/ruby/2.2.0/gems/bundler-1.9.7/lib/bundler/runtime.rb:85:in `require'
Oct 09 17:04:27 doremi app/worker.1: /app/vendor/bundle/ruby/2.2.0/gems/bundler-1.9.7/lib/bundler/runtime.rb:85:in `rescue in block in require'
Oct 09 17:04:27 doremi app/worker.1: /app/vendor/bundle/ruby/2.2.0/gems/bundler-1.9.7/lib/bundler/runtime.rb:68:in `block in require'
Oct 09 17:04:27 doremi app/worker.1: /app/vendor/bundle/ruby/2.2.0/gems/bundler-1.9.7/lib/bundler/runtime.rb:61:in `each'
Oct 09 17:04:27 doremi app/worker.1: /app/vendor/bundle/ruby/2.2.0/gems/bundler-1.9.7/lib/bundler/runtime.rb:61:in `require'
Oct 09 17:04:27 doremi app/worker.1: /app/vendor/bundle/ruby/2.2.0/gems/bundler-1.9.7/lib/bundler.rb:134:in `require'
Oct 09 17:04:27 doremi app/worker.1: /app/config/application.rb:16:in `<top (required)>'
Oct 09 17:04:27 doremi app/worker.1: /app/Rakefile:4:in `require'
Oct 09 17:04:27 doremi app/worker.1: /app/Rakefile:4:in `<top (required)>'
Oct 09 17:04:27 doremi app/worker.1: LoadError: cannot load such file -- bonsai-elasticsearch-rails
Oct 09 17:04:27 doremi app/worker.1: /app/vendor/bundle/ruby/2.2.0/gems/bundler-1.9.7/lib/bundler/runtime.rb:76:in `require'
Oct 09 17:04:27 doremi app/worker.1: /app/vendor/bundle/ruby/2.2.0/gems/bundler-1.9.7/lib/bundler/runtime.rb:76:in `block (2 levels) in require'
Oct 09 17:04:27 doremi app/worker.1: /app/vendor/bundle/ruby/2.2.0/gems/bundler-1.9.7/lib/bundler/runtime.rb:72:in `each'
Oct 09 17:04:27 doremi app/worker.1: /app/vendor/bundle/ruby/2.2.0/gems/bundler-1.9.7/lib/bundler/runtime.rb:72:in `block in require'
Oct 09 17:04:27 doremi app/worker.1: /app/vendor/bundle/ruby/2.2.0/gems/bundler-1.9.7/lib/bundler/runtime.rb:61:in `each'
Oct 09 17:04:27 doremi app/worker.1: /app/vendor/bundle/ruby/2.2.0/gems/bundler-1.9.7/lib/bundler/runtime.rb:61:in `require'
Oct 09 17:04:27 doremi app/worker.1: /app/vendor/bundle/ruby/2.2.0/gems/bundler-1.9.7/lib/bundler.rb:134:in `require'
Oct 09 17:04:27 doremi app/worker.1: /app/config/application.rb:16:in `<top (required)>'
Oct 09 17:04:27 doremi app/worker.1: /app/Rakefile:4:in `require'
Oct 09 17:04:27 doremi app/worker.1: /app/Rakefile:4:in `<top (required)>'