You can certainly log out some environment variables in Travis CI but be careful that you do not log out secret information in your logs.
Travis Web UI logging
Steps that Travis CI takes to protect your environment-specific variables
Travis CI will, by default, hide any variables such as tokens and environment variables and simply display the string [secure] in their place.
If you go to build #3 https://travis-ci.org/packtci/puppeteer-headless-chrome-travis-yml-script/builds/398696669), you will see the following entry:
Remember that we added the following encrypted environment variable in this repository in Chapter 10, Travis CI CLI Commands and Automation:
travis encrypt SECRET_VALUE=SuperSecret12345 --add
Notice that this...