Hosts: feature breaks /etc/hosts file and gradle

Hi,

We use an older version of gradle which is determined to use jcenter (which surprisingly is still around but occasionally has issues). When I updated our gradle build to have

hosts:
     - https://jcenter.bintray.com

so we could ensure we would not inadvertently use jcenter. However, when I do this, I started seeing gradle build failing after compilation with

Could not stop org.gradle.internal.build.event.DefaultBuildEventsListenerRegistry$ForwardingBuildEventConsumer@a46dd39.

org.gradle.api.UncheckedIOException: java.net.UnknownHostException: travis-job-cmus-data-xchange-76366469: travis-job-cmus-data-xchange-76366469: Name or service not known

I thought perhaps something was going wrong with the hosts file, so I added

  - ls -alt /etc/hosts
  - sudo chmod +r /etc/hosts
  - sudo cat /etc/hosts

to my travis.yaml. However, they “succeed” with the following errors:

$ ls -alt /etc/hosts
-rw-r--r-- 1 root root 0 Sep 26 14:42 /etc/hosts
install.2

0.03s$ sudo chmod +r /etc/hosts

sudo: unable to resolve host travis-job-cmus-data-xchange-76366469
install.3
0.03s$ sudo cat /etc/hosts
sudo: unable to resolve host travis-job-cmus-data-xchange-76366469

I unfortunately cannot provide a link to the build, as it is in a private travis repository my company hosts.

Here’s the .travis.yml up to the point it fails. Note this passes if I remove the hosts block. I don’t think the actual code is relevant. If there’s anything else I can provide, please let me know.

language: java
sudo: required
dist: xenial

services:
  - docker

network: bluezone

addons:
  hosts:
    - https://jcenter.bintray.com

git:
    depth: 6

install:
  #Run code compilation here. If it fails, the build fails immediately
  - ls -alt /etc/hosts
  - sudo chmod +r /etc/hosts
  - sudo cat /etc/hosts
  - ./gradlew shadowJar

Here shadowJar comes from id 'com.github.johnrengelman.shadow' version '5.1.0'

Thank you!