EFES (EpiDoc Front End Services) is a custom and readily customizable platform for publication and search/indexing of EpiDoc files, based on the Kiln platform
With the addition of user-indices, the Solr file_path field as the means of identifying which Solr documents to remove on indexing needs to trigger off something other than the actual file path. "source_id" is a better name for the field.
Except that's not actually true, since the file path of the index file that defines the user-indices is a perfectly good identifier. This may need to change in future, but for now it's fine.
With the addition of user-indices, the Solr file_path field as the means of identifying which Solr documents to remove on indexing needs to trigger off something other than the actual file path. "source_id" is a better name for the field.