> My reasoning is that stuff like WEB_FIXTURE_HOST make sense to change them locally, so it is handy to put take them from the environment

It was actually my mistake when I added then. They should have been `<env ` instead of `<server ` for Travis to pick up.

> On the other hand, driver_config_factory does not make snese to be changed in a local setup. It is a configuration of the testsuite itself, just because it is generic (PHPCR-api-tests goes even further by forcing testsuites to define a ImplementationLoader class and hardcoding it, but I prefer to make it configurable).

OK.