I am seeing a strange behaviour where Travis CI uses Ubuntu images instead of Debian images…
Locally:
$ docker run -it debian:stretch uname -a
Linux cca6aea0eebf 4.9.0-8-amd64 #1 SMP Debian 4.9.110-3+deb9u3 (2018-08-19) x86_64 GNU/Linux
On Travis CI:
$ docker run -it debian:stretch uname -a
Linux 50da2fcf2251 4.4.0-101-generic #124~14.04.1-Ubuntu SMP Fri Nov 10 19:05:36 UTC 2017 x86_64 GNU/Linux
Steps to reproduce:
https://travis-ci.org/laughingbiscuit/travis-weirdness/builds/447521531#L453
Please note, I am using a node-js environment as my project runs cucumber-js tests against a Docker container.