Cannot define multiple 'included' blocks for a Concern (ActiveSupport::Concern::MultipleIncludedBlocks) with cache_classes = true
For anyone hitting the same wall to read, the solution to this is to strictly respect Rails autoloading rules. That is
- Removing all the require / require_relative
- Add needed paths to Rails autoload paths
- Put files at the right places with the right names so Rails can infer where to look for code to load.
More info here: https://github.com/rails/rails/issues/15767
It's also possible that you have two concerns with same name.
In my case I faced this error while running rails swagger:docs SD_LOG_LEVEL=1 .
$ rails swagger:docs SD_LOG_LEVEL=1Cannot define multiple 'included' blocks for a Concern1.0: 19 processed / 49 skippedSince I had two swagger files with same name.
module SwaggerDocs::TrackerPhases extend ActiveSupport::Concern included do endendmodule SwaggerDocs::TrackerPhases extend ActiveSupport::Concern included do endendI renamed second file as:
module SwaggerDocs::ClientTrackerPhases extend ActiveSupport::Concern included do endend