rails Dockerfile docker-compose を別pjから移したときにGemfile.lockが原因で起動しなかった

docker-compose.yml、Dockerfileなどを別プロジェクトから移行してきたときに以下のようなエラーが出て起動できなかった。メモ用に

エラー

$ docker-compose up --build

を実行したときに以下のようなエラーが出た

app_1  | Bundler::GemNotFound: Could not find gem 'mysql2 (>= 0.4.4)' in any of the gem sources listed in your Gemfile.
app_1  |   /usr/local/lib/ruby/2.6.0/bundler/resolver.rb:287:in `block in verify_gemfile_dependencies_are_found!'
app_1  |   /usr/local/lib/ruby/2.6.0/bundler/resolver.rb:255:in `each'
app_1  |   /usr/local/lib/ruby/2.6.0/bundler/resolver.rb:255:in `verify_gemfile_dependencies_are_found!'
app_1  |   /usr/local/lib/ruby/2.6.0/bundler/resolver.rb:49:in `start'
app_1  |   /usr/local/lib/ruby/2.6.0/bundler/resolver.rb:22:in `resolve'
app_1  |   /usr/local/lib/ruby/2.6.0/bundler/definition.rb:258:in `resolve'
app_1  |   /usr/local/lib/ruby/2.6.0/bundler/definition.rb:170:in `specs'
app_1  |   /usr/local/lib/ruby/2.6.0/bundler/definition.rb:237:in `specs_for'
app_1  |   /usr/local/lib/ruby/2.6.0/bundler/definition.rb:226:in `requested_specs'
app_1  |   /usr/local/lib/ruby/2.6.0/bundler/runtime.rb:108:in `block in definition_method'
app_1  |   /usr/local/lib/ruby/2.6.0/bundler/runtime.rb:20:in `setup'
app_1  |   /usr/local/lib/ruby/2.6.0/bundler.rb:107:in `setup'
app_1  |   /usr/local/lib/ruby/2.6.0/bundler/setup.rb:20:in `<top (required)>'
app_1  |   /usr/local/lib/ruby/2.6.0/rubygems/core_ext/kernel_require.rb:54:in `require'
app_1  |   /usr/local/lib/ruby/2.6.0/rubygems/core_ext/kernel_require.rb:54:in `require'
app_1  | bundler: failed to load command: puma (/webapp/vendor/bundle/ruby/2.6.0/bin/puma)

解決

Gemfile.lockの中身を削除して再度 docker-compose up --buildを再度実行。
必要に応じてコンテナ内でbundle installを実行する