I found Dancer to swallow error messages and die messages, and also to swallow output when warnings are issued during the runtime.

The workaround I've used in anger is to wrap my code in my own eval and the output the caught information myself. Which defeats the point of using a framework.

In your case, I would look closely at whether the code could die (maybe $rootdir doesn't exist, etc.) or whether it could output warnings (which doesn't seem to be likely).

Update: See CountZeros reply, which is the more propable cause I guess - your handler needs to return the proper content through template, so template should be mostly called as

return template ...;
[download]