Try an IPv6 workaround for the Linux builds.

diff --git a/.travis.yml b/.travis.yml
index c5279874fd9b98fabcb1320b77acffb1730d3b47..674a4cb89de6e97790c9c83fb89072a9fdb334ce 100644 (file)
--- a/.travis.yml
+++ b/.travis.yml
@@ -12,6 +12,8 @@ matrix:
     - os: linux
       dist: focal
       virt: vm
+      sudo: required
+      group: deprecated-2017Q4
       addons:
         apt:
           packages: [libavahi-client-dev, libgnutls28-dev, zlib1g-dev]