Precedence of repository env vars vs env vars in .travis.yml file

From the Travis logs, it appears the section “Setting environment variables from repository settings” happens before the section “Setting environment variables from .travis.yml”. This means that the environment variables hard-coded in the .travis.yml file have precedence over anything I define in the repository settings. Is that deliberate? Now and again, I would like to override the environment variables hard-coded in the .travis.yml file, but the way things are at the moment, I can’t. It would be hugely useful if the repo env vars were set after the .travis.yml file env vars.

See the environment variable TRVS_VERBOSE in this log for an example:
https://travis-ci.com/github/keitherskine/pyodbc/jobs/343766209