Consider generating an error on include loops #30
Description
It is currently possible for fragment A to include fragment B which includes fragment A. This causes no problems as de-duplication occurs and the second include is ignored. The question is should it be a problem conceptually? Where should we detect this problem? It seems like it can only be detected safely when are processing an injector, in which case does it add additional complexity/cost and if so is it worth it?
If we decide this will not be done then we should also mark #29 as willnotfix