@JelmerD you've changed what this method does to be different from it's name - and without changing any doc blocks or tests. Changing the error handler to dump content inline will just break things.

What you appear to be describing in the ticket description is "it doesn't work the way I want to use it" - that's because it's not designed to do what you're doing. It should be a hint that you're trying to fix something related to css by modifying Cake's error handler.

There's no need to point out the reason for the travis fails, we can read the reports =).