Ok I have now switched to CentOS 8 and installed aaPanel and ES.
I’m running Ruby 2.5.5 and if I now “gem install bundler rake rails”
then this message comes
[zammad@vmd42762 ~]$ gem install bundler rake rails
Fetching: bundler-2.1.4.gem (100%)
Successfully installed bundler-2.1.4
Parsing documentation for bundler-2.1.4
Installing ri documentation for bundler-2.1.4
Done installing documentation for bundler after 7 seconds
Fetching: rake-13.0.1.gem (100%)
Successfully installed rake-13.0.1
Parsing documentation for rake-13.0.1
Installing ri documentation for rake-13.0.1
Done installing documentation for rake after 0 seconds
Fetching: concurrent-ruby-1.1.6.gem (100%)
Successfully installed concurrent-ruby-1.1.6
Fetching: i18n-1.8.2.gem (100%)
HEADS UP! i18n 1.1 changed fallbacks to exclude default locale.
But that may break your application.
If you are upgrading your Rails application from an older version of Rails:
Please check your Rails app for 'config.i18n.fallbacks = true'.
If you're using I18n (>= 1.1.0) and Rails (< 5.2.2), this should be
'config.i18n.fallbacks = [I18n.default_locale]'.
If not, fallbacks will be broken in your app by I18n 1.1.x.
If you are starting a NEW Rails application, you can ignore this notice.
For more info see:
Successfully installed i18n-1.8.2
Fetching: thread_safe-0.3.6.gem (100%)
Successfully installed thread_safe-0.3.6
Fetching: tzinfo-1.2.6.gem (100%)
Successfully installed tzinfo-1.2.6
Fetching: minitest-5.14.0.gem (100%)
Successfully installed minitest-5.14.0
Fetching: zeitwerk-2.2.2.gem (100%)
Successfully installed zeitwerk-2.2.2
Fetching: activesupport-18.104.22.168.gem (100%)
Successfully installed activesupport-22.214.171.124
Fetching: rack-2.2.2.gem (100%)
Successfully installed rack-2.2.2
Fetching: rack-test-1.1.0.gem (100%)
Successfully installed rack-test-1.1.0
Fetching: mini_portile2-2.4.0.gem (100%)
Successfully installed mini_portile2-2.4.0
Fetching: nokogiri-1.10.8.gem (100%)
Building native extensions. This could take a while...
ERROR: Error installing rails:
ERROR: Failed to build gem native extension.
current directory: /opt/zammad/.gem/ruby/gems/nokogiri-1.10.8/ext/nokogiri
/usr/bin/ruby -r ./siteconf20200213-16591-1azjok3.rb extconf.rb
mkmf.rb can't find header files for ruby at /usr/share/include/ruby.h
extconf failed, exit code 1
Gem files will remain installed in /opt/zammad/.gem/ruby/gems/nokogiri-1.10.8 for inspection.
Results logged to /opt/zammad/.gem/ruby/extensions/x86_64-linux/2.5.0/nokogiri-1.10.8/gem_make.out
2 gems installed