Merge branch 'feature/make-2.6-compatible' into 'releases/2.6'

Patch releases/2.6 branch to work with 2.6 releases

See merge request !178
5 jobs for v2.6.0 in 11 minutes and 5 seconds (queued for 1 second)
latest
Status Job ID Name Coverage
  Test
passed #42034
duneci
debian:10 gcc:c++17

00:11:05

passed #42036
duneci
debian:9--clang

00:08:26

passed #42035
duneci
debian:9--gcc

00:08:29

passed #42038
duneci
ubuntu:16.04--clang

00:08:25

passed #42037
duneci
ubuntu:16.04--gcc

00:04:32