Thanks John for the info... I did that and now I'm missing a file. I tried to ask yum what package I need - but It did not know. Building native extensions. This could take a while... ERROR: Failed to build gem native extension. /opt/rh/rh-ruby22/root/usr/bin/ruby -r ./siteconf20190805-94063-1gebs0u.rb extconf.rb mkmf.rb can't find header files for ruby at /opt/rh/rh-ruby22/root/usr/share/include/ruby.h extconf failed, exit code 1 Gem files will remain installed in /opt/rh/rh-ruby22/root/usr/local/share/gems/gems/nio4r-1.1.1 for inspection. Results logged to /opt/rh/rh-ruby22/root/usr/local/lib64/gems/ruby/nio4r-1.1.1/gem_make.out yum provides /opt/rh/rh-ruby22/root/usr/share/include/ruby.h Loaded plugins: fastestmirror, langpacks, nvidia Loading mirror speeds from cached hostfile * base: mirror.tzulo.com * centos-sclo-rh: mirror.team-cymru.com * centos-sclo-sclo: mirror.fileplanet.com * elrepo: ord.mirror.rackspace.com * epel: ord.mirror.rackspace.com * extras: mirror.nodesdirect.com * updates: mirrors.liquidweb.com centos-sclo-rh/x86_64/filelists_db | 12 MB 00:00:01 elrepo/filelists_db | 34 kB 00:00:00 epel/x86_64/filelists_db | 12 MB 00:00:00 google-chrome/filelists | 1.7 kB 00:00:00 updates/7/x86_64/filelists_db | 5.2 MB 00:00:00 No matches found Thanks, What is next ? Jerry >