Created attachment 239734 [details] Patch file Mark BROKEN with Ruby 3.1. Full build log: https://people.freebsd.org/~yasu/poudriere/data/logs/bulk/131amd64-default-ruby/2023-01-27_11h29m27s/logs/rubygem-ruby-augeas-0.5.0_4.log
It has come to light that the source of build error is bug of mkmf library in Ruby 3.1. I submitted patch to fix it as bug #269197 and by applying it build of this port succeeds with Ruby 3.1.
After ports fc1c752e8b1c is committed build with Ruby 3.1 succeeds now.