Rails 7 - uninitialized constant Impressionist::Engine::ImpressionistController (NameError)

[raguila8]

After upgrading to rails 7 I'm getting the below error with the impressionist gem. When I start my local server.
uninitialized constant Impressionist::Engine::ImpressionistController (NameError)
ruby 3.0.2
rails 7.0.1
gem "impressionist", git: "https://github.com/charlotte-ruby/impressionist

This is the full stack after installing with bundler and running rails g impressionist:

/Users/rodi/.rbenv/versions/3.0.2/lib/ruby/gems/3.0.0/gems/impressionist-2.0.0/lib/impressionist/engine.rb:15:in `block (2 levels) in <class:Engine>': uninitialized constant Impressionist::Engine::ImpressionistController (NameError)
	from /Users/rodi/.rbenv/versions/3.0.2/lib/ruby/gems/3.0.0/gems/activesupport-7.0.1/lib/active_support/lazy_load_hooks.rb:71:in `class_eval'
	from /Users/rodi/.rbenv/versions/3.0.2/lib/ruby/gems/3.0.0/gems/activesupport-7.0.1/lib/active_support/lazy_load_hooks.rb:71:in `block in execute_hook'
	from /Users/rodi/.rbenv/versions/3.0.2/lib/ruby/gems/3.0.0/gems/activesupport-7.0.1/lib/active_support/lazy_load_hooks.rb:61:in `with_execution_control'
	from /Users/rodi/.rbenv/versions/3.0.2/lib/ruby/gems/3.0.0/gems/activesupport-7.0.1/lib/active_support/lazy_load_hooks.rb:66:in `execute_hook'
	from /Users/rodi/.rbenv/versions/3.0.2/lib/ruby/gems/3.0.0/gems/activesupport-7.0.1/lib/active_support/lazy_load_hooks.rb:43:in `block in on_load'
	from /Users/rodi/.rbenv/versions/3.0.2/lib/ruby/gems/3.0.0/gems/activesupport-7.0.1/lib/active_support/lazy_load_hooks.rb:42:in `each'
	from /Users/rodi/.rbenv/versions/3.0.2/lib/ruby/gems/3.0.0/gems/activesupport-7.0.1/lib/active_support/lazy_load_hooks.rb:42:in `on_load'
	from /Users/rodi/.rbenv/versions/3.0.2/lib/ruby/gems/3.0.0/gems/impressionist-2.0.0/lib/impressionist/engine.rb:14:in `block in <class:Engine>'
	from /Users/rodi/.rbenv/versions/3.0.2/lib/ruby/gems/3.0.0/gems/railties-7.0.1/lib/rails/initializable.rb:32:in `instance_exec'
	from /Users/rodi/.rbenv/versions/3.0.2/lib/ruby/gems/3.0.0/gems/railties-7.0.1/lib/rails/initializable.rb:32:in `run'
	from /Users/rodi/.rbenv/versions/3.0.2/lib/ruby/gems/3.0.0/gems/railties-7.0.1/lib/rails/initializable.rb:61:in `block in run_initializers'
	from /Users/rodi/.rbenv/versions/3.0.2/lib/ruby/3.0.0/tsort.rb:228:in `block in tsort_each'
	from /Users/rodi/.rbenv/versions/3.0.2/lib/ruby/3.0.0/tsort.rb:350:in `block (2 levels) in each_strongly_connected_component'
	from /Users/rodi/.rbenv/versions/3.0.2/lib/ruby/3.0.0/tsort.rb:431:in `each_strongly_connected_component_from'
	from /Users/rodi/.rbenv/versions/3.0.2/lib/ruby/3.0.0/tsort.rb:349:in `block in each_strongly_connected_component'
	from /Users/rodi/.rbenv/versions/3.0.2/lib/ruby/3.0.0/tsort.rb:347:in `each'
	from /Users/rodi/.rbenv/versions/3.0.2/lib/ruby/3.0.0/tsort.rb:347:in `call'
	from /Users/rodi/.rbenv/versions/3.0.2/lib/ruby/3.0.0/tsort.rb:347:in `each_strongly_connected_component'
	from /Users/rodi/.rbenv/versions/3.0.2/lib/ruby/3.0.0/tsort.rb:226:in `tsort_each'
	from /Users/rodi/.rbenv/versions/3.0.2/lib/ruby/3.0.0/tsort.rb:205:in `tsort_each'
	from /Users/rodi/.rbenv/versions/3.0.2/lib/ruby/gems/3.0.0/gems/railties-7.0.1/lib/rails/initializable.rb:60:in `run_initializers'
	from /Users/rodi/.rbenv/versions/3.0.2/lib/ruby/gems/3.0.0/gems/railties-7.0.1/lib/rails/application.rb:372:in `initialize!'
	from /Users/rodi/workspace/projects/tailwind_awesome/config/environment.rb:5:in `<main>'
	from /Users/rodi/.rbenv/versions/3.0.2/lib/ruby/gems/3.0.0/gems/bootsnap-1.9.4/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:23:in `require'
	from /Users/rodi/.rbenv/versions/3.0.2/lib/ruby/gems/3.0.0/gems/bootsnap-1.9.4/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:23:in `block in require_with_bootsnap_lfi'
	from /Users/rodi/.rbenv/versions/3.0.2/lib/ruby/gems/3.0.0/gems/bootsnap-1.9.4/lib/bootsnap/load_path_cache/loaded_features_index.rb:88:in `register'
	from /Users/rodi/.rbenv/versions/3.0.2/lib/ruby/gems/3.0.0/gems/bootsnap-1.9.4/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:22:in `require_with_bootsnap_lfi'
	from /Users/rodi/.rbenv/versions/3.0.2/lib/ruby/gems/3.0.0/gems/bootsnap-1.9.4/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:31:in `require'
	from /Users/rodi/.rbenv/versions/3.0.2/lib/ruby/gems/3.0.0/gems/zeitwerk-2.5.3/lib/zeitwerk/kernel.rb:35:in `require'
	from /Users/rodi/.rbenv/versions/3.0.2/lib/ruby/gems/3.0.0/gems/railties-7.0.1/lib/rails/application.rb:348:in `require_environment!'
	from /Users/rodi/.rbenv/versions/3.0.2/lib/ruby/gems/3.0.0/gems/railties-7.0.1/lib/rails/command/actions.rb:28:in `require_environment!'
	from /Users/rodi/.rbenv/versions/3.0.2/lib/ruby/gems/3.0.0/gems/railties-7.0.1/lib/rails/command/actions.rb:15:in `require_application_and_environment!'
	from /Users/rodi/.rbenv/versions/3.0.2/lib/ruby/gems/3.0.0/gems/railties-7.0.1/lib/rails/commands/generate/generate_command.rb:21:in `perform'
	from /Users/rodi/.rbenv/versions/3.0.2/lib/ruby/gems/3.0.0/gems/thor-1.2.1/lib/thor/command.rb:27:in `run'
	from /Users/rodi/.rbenv/versions/3.0.2/lib/ruby/gems/3.0.0/gems/thor-1.2.1/lib/thor/invocation.rb:127:in `invoke_command'
	from /Users/rodi/.rbenv/versions/3.0.2/lib/ruby/gems/3.0.0/gems/thor-1.2.1/lib/thor.rb:392:in `dispatch'
	from /Users/rodi/.rbenv/versions/3.0.2/lib/ruby/gems/3.0.0/gems/railties-7.0.1/lib/rails/command/base.rb:87:in `perform'
	from /Users/rodi/.rbenv/versions/3.0.2/lib/ruby/gems/3.0.0/gems/railties-7.0.1/lib/rails/command.rb:48:in `invoke'
	from /Users/rodi/.rbenv/versions/3.0.2/lib/ruby/gems/3.0.0/gems/railties-7.0.1/lib/rails/commands.rb:18:in `<main>'
	from /Users/rodi/.rbenv/versions/3.0.2/lib/ruby/gems/3.0.0/gems/bootsnap-1.9.4/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:23:in `require'
	from /Users/rodi/.rbenv/versions/3.0.2/lib/ruby/gems/3.0.0/gems/bootsnap-1.9.4/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:23:in `block in require_with_bootsnap_lfi'
	from /Users/rodi/.rbenv/versions/3.0.2/lib/ruby/gems/3.0.0/gems/bootsnap-1.9.4/lib/bootsnap/load_path_cache/loaded_features_index.rb:105:in `register'
	from /Users/rodi/.rbenv/versions/3.0.2/lib/ruby/gems/3.0.0/gems/bootsnap-1.9.4/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:22:in `require_with_bootsnap_lfi'
	from /Users/rodi/.rbenv/versions/3.0.2/lib/ruby/gems/3.0.0/gems/bootsnap-1.9.4/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:31:in `require'
	from bin/rails:4:in `<main>'

[stingo]

Facing the same issue with my existing app after an upgrade to rails 7 and ruby 3.0.1

/.rbenv/versions/3.0.3/lib/ruby/gems/3.0.0/bundler/gems/impressionist-e0db056a2ac0/lib/impressionist/engine.rb:15:in `block (2 levels) in <class:Engine>': uninitialized constant Impressionist::Engine::ImpressionistController (NameError)
	from /Users/charliewiredu/.rbenv/versions/3.0.3/lib/ruby/gems/3.0.0/gems/activesupport-7.0.1/lib/active_support/lazy_load_hooks.rb:71:in `class_eval'
	from /Users/charliewiredu/.rbenv/versions/3.0.3/lib/ruby/gems/3.0.0/gems/activesupport-7.0.1/lib/active_support/lazy_load_hooks.rb:71:in `block in execute_hook'
	from /Users/charliewiredu/.rbenv/versions/3.0.3/lib/ruby/gems/3.0.0/gems/activesupport-7.0.1/lib/active_support/lazy_load_hooks.rb:61:in `with_execution_control'
	from /Users/charliewiredu/.rbenv/versions/3.0.3/lib/ruby/gems/3.0.0/gems/activesupport-7.0.1/lib/active_support/lazy_load_hooks.rb:66:in `execute_hook'
	from /Users/charliewiredu/.rbenv/versions/3.0.3/lib/ruby/gems/3.0.0/gems/activesupport-7.0.1/lib/active_support/lazy_load_hooks.rb:43:in `block in on_load'
	from /Users/charliewiredu/.rbenv/versions/3.0.3/lib/ruby/gems/3.0.0/gems/activesupport-7.0.1/lib/active_support/lazy_load_hooks.rb:42:in `each'
	from /Users/charliewiredu/.rbenv/versions/3.0.3/lib/ruby/gems/3.0.0/gems/activesupport-7.0.1/lib/active_support/lazy_load_hooks.rb:42:in `on_load'
	from /Users/charliewiredu/.rbenv/versions/3.0.3/lib/ruby/gems/3.0.0/bundler/gems/impressionist-e0db056a2ac0/lib/impressionist/engine.rb:14:in `block in <class:Engine>'
	from /Users/charliewiredu/.rbenv/versions/3.0.3/lib/ruby/gems/3.0.0/gems/railties-7.0.1/lib/rails/initializable.rb:32:in `instance_exec'
	from /Users/charliewiredu/.rbenv/versions/3.0.3/lib/ruby/gems/3.0.0/gems/railties-7.0.1/lib/rails/initializable.rb:32:in `run'
	from /Users/charliewiredu/.rbenv/versions/3.0.3/lib/ruby/gems/3.0.0/gems/railties-7.0.1/lib/rails/initializable.rb:61:in `block in run_initializers'
	from /Users/charliewiredu/.rbenv/versions/3.0.3/lib/ruby/3.0.0/tsort.rb:228:in `block in tsort_each'
	from /Users/charliewiredu/.rbenv/versions/3.0.3/lib/ruby/3.0.0/tsort.rb:350:in `block (2 levels) in each_strongly_connected_component'
	from /Users/charliewiredu/.rbenv/versions/3.0.3/lib/ruby/3.0.0/tsort.rb:431:in `each_strongly_connected_component_from'
	from /Users/charliewiredu/.rbenv/versions/3.0.3/lib/ruby/3.0.0/tsort.rb:349:in `block in each_strongly_connected_component'
	from /Users/charliewiredu/.rbenv/versions/3.0.3/lib/ruby/3.0.0/tsort.rb:347:in `each'
	from /Users/charliewiredu/.rbenv/versions/3.0.3/lib/ruby/3.0.0/tsort.rb:347:in `call'
	from /Users/charliewiredu/.rbenv/versions/3.0.3/lib/ruby/3.0.0/tsort.rb:347:in `each_strongly_connected_component'
	from /Users/charliewiredu/.rbenv/versions/3.0.3/lib/ruby/3.0.0/tsort.rb:226:in `tsort_each'
	from /Users/charliewiredu/.rbenv/versions/3.0.3/lib/ruby/3.0.0/tsort.rb:205:in `tsort_each'
	from /Users/charliewiredu/.rbenv/versions/3.0.3/lib/ruby/gems/3.0.0/gems/railties-7.0.1/lib/rails/initializable.rb:60:in `run_initializers'
	from /Users/charliewiredu/.rbenv/versions/3.0.3/lib/ruby/gems/3.0.0/gems/railties-7.0.1/lib/rails/application.rb:372:in `initialize!'
	from /Users/charliewiredu/Dev/uppro/config/environment.rb:5:in `<main>'
	from /Users/charliewiredu/.rbenv/versions/3.0.3/lib/ruby/gems/3.0.0/gems/bootsnap-1.10.2/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:30:in `require'
	from /Users/charliewiredu/.rbenv/versions/3.0.3/lib/ruby/gems/3.0.0/gems/bootsnap-1.10.2/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:30:in `require'
	from /Users/charliewiredu/.rbenv/versions/3.0.3/lib/ruby/gems/3.0.0/gems/zeitwerk-2.5.4/lib/zeitwerk/kernel.rb:35:in `require'
	from /Users/charliewiredu/.rbenv/versions/3.0.3/lib/ruby/gems/3.0.0/gems/bootsnap-1.10.2/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:42:in `require_relative'
	from config.ru:3:in `block in <main>'
	from /Users/charliewiredu/.rbenv/versions/3.0.3/lib/ruby/gems/3.0.0/gems/rack-2.2.3/lib/rack/builder.rb:116:in `eval'
	from /Users/charliewiredu/.rbenv/versions/3.0.3/lib/ruby/gems/3.0.0/gems/rack-2.2.3/lib/rack/builder.rb:116:in `new_from_string'
	from /Users/charliewiredu/.rbenv/versions/3.0.3/lib/ruby/gems/3.0.0/gems/rack-2.2.3/lib/rack/builder.rb:105:in `load_file'
	from /Users/charliewiredu/.rbenv/versions/3.0.3/lib/ruby/gems/3.0.0/gems/rack-2.2.3/lib/rack/builder.rb:66:in `parse_file'
	from /Users/charliewiredu/.rbenv/versions/3.0.3/lib/ruby/gems/3.0.0/gems/rack-2.2.3/lib/rack/server.rb:349:in `build_app_and_options_from_config'
	from /Users/charliewiredu/.rbenv/versions/3.0.3/lib/ruby/gems/3.0.0/gems/rack-2.2.3/lib/rack/server.rb:249:in `app'
	from /Users/charliewiredu/.rbenv/versions/3.0.3/lib/ruby/gems/3.0.0/gems/rack-2.2.3/lib/rack/server.rb:422:in `wrapped_app'
	from /Users/charliewiredu/.rbenv/versions/3.0.3/lib/ruby/gems/3.0.0/gems/railties-7.0.1/lib/rails/commands/server/server_command.rb:76:in `log_to_stdout'
	from /Users/charliewiredu/.rbenv/versions/3.0.3/lib/ruby/gems/3.0.0/gems/railties-7.0.1/lib/rails/commands/server/server_command.rb:36:in `start'
	from /Users/charliewiredu/.rbenv/versions/3.0.3/lib/ruby/gems/3.0.0/gems/railties-7.0.1/lib/rails/commands/server/server_command.rb:143:in `block in perform'
	from <internal:kernel>:90:in `tap'
	from /Users/charliewiredu/.rbenv/versions/3.0.3/lib/ruby/gems/3.0.0/gems/railties-7.0.1/lib/rails/commands/server/server_command.rb:134:in `perform'
	from /Users/charliewiredu/.rbenv/versions/3.0.3/lib/ruby/gems/3.0.0/gems/thor-1.2.1/lib/thor/command.rb:27:in `run'
	from /Users/charliewiredu/.rbenv/versions/3.0.3/lib/ruby/gems/3.0.0/gems/thor-1.2.1/lib/thor/invocation.rb:127:in `invoke_command'
	from /Users/charliewiredu/.rbenv/versions/3.0.3/lib/ruby/gems/3.0.0/gems/thor-1.2.1/lib/thor.rb:392:in `dispatch'
	from /Users/charliewiredu/.rbenv/versions/3.0.3/lib/ruby/gems/3.0.0/gems/railties-7.0.1/lib/rails/command/base.rb:87:in `perform'
	from /Users/charliewiredu/.rbenv/versions/3.0.3/lib/ruby/gems/3.0.0/gems/railties-7.0.1/lib/rails/command.rb:48:in `invoke'
	from /Users/charliewiredu/.rbenv/versions/3.0.3/lib/ruby/gems/3.0.0/gems/railties-7.0.1/lib/rails/commands.rb:18:in `<main>'
	from /Users/charliewiredu/.rbenv/versions/3.0.3/lib/ruby/gems/3.0.0/gems/bootsnap-1.10.2/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:30:in `require'
	from /Users/charliewiredu/.rbenv/versions/3.0.3/lib/ruby/gems/3.0.0/gems/bootsnap-1.10.2/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:30:in `require'
	from bin/rails:4:in `<main>'

[JamesDullaghan]

Same as above

[mokevnin]

found temporary solution:

# add to application.rb at the top
impressionist_dir = Gem::Specification.find_by_name('impressionist').gem_dir
require File.join(impressionist_dir, '/app/controllers/impressionist_controller.rb')

Enjoy :)