CentOS 7’s default compiler is GCC 4.8.5. It will have full updates until 2020-08-06. I am currently running nightly valgrind and coverages for ITK on this OS. And use it for SimpleITK CI with a variety of different compilers. However, with the change in direction of CentOS, another Linux distribution will likely be used in the near future.
Redhat 7 is corresponding version for CentOS 7 also has GCC 4.8.5. Redhat is rather notorious for long enterprise support. It use used on all the cluster I work with. Redhat 7 EOL date is 6/30/2024.
I do not propose we support the compiler until this date, but it is a sensible upper bound in this discussion.
It would be nice to have a table to common Linux distro’s, gcc versions and EOL dates. I don’t have time to continue the search. This would provide some additional reasoning for the change is supported compilers on a minor change of the toolkit.
Dropping less than (but not) 4.8.5 would not cause a problem with anything I am using right now.
*EDIT: Dzenan pointed out that the valgrind and coverage builds are failing on the dashboard.