I modified the example given in the ExternalProcesses wiki page to return exactly the request line and queried the external process with both a trailing slash ( http://127.0.0.1:5984/test/_test/ ) and no trailing slash ( http://127.0.0.1:5984/test/_test ). The request line is exactly the same for these two cases.
This is problematic because external processes may treat these cases differently. For example, Django's CommonMiddleware class redirects any "path" to "path/" if there is a view at "path/" but not at "path", which is usually the case for a default view of a Django app. When using Django with couchdb-wsgi, this results in an infinite redirect loop because although Django issues a redirect to "path/", couchdb-wsgi emits "path" as the path.