Centos8 should be supported as of v6.2.0:
Any modules requiring puppet-concat as a dependency should require at least v6.2.0
#1 Updated by Ewoud Kohl van Wijngaarden over 2 years ago
I'd disagree that we should require at least 6.2.0 in modules. Modules can work just fine with older versions.
A more correct check is to ensure we ship at least 6.2.0 in the installer. https://github.com/theforeman/foreman-installer/pull/467 would be a more dynamic way to verify this.