How to tell if there's a render error when manually rendering a Django template?
Sadly enough hacking around the problem like that is the best solution available. It should be noted that the variable is called TEMPLATE_STRING_IF_INVALID btw.
Alternatively I would recommend using Jinja2 together with Coffin, that makes debugging a lot easier as well and Jinja2 actually does give proper stacktraces for errors like these.
I'm using the Django template system for some form emails, with the templates editable by the end user. 
A template's render method returns the rendered content and silently passes over invalid variables and tags. Is there a reasonable way to tell if there was an error during rendering?
I've considering setting settings.TEMPLATE_STRING_IF_INVALID to a unique string and then testing for the presence of this string but that would affect normal template rendering, which isn't acceptable. I've scanned Django's source code in the hope there is a "render invalid variable/tag" method I can override cleanly to raise an exception, but no such luck. 
Any ideas?