Satellite 6 installer fails with 'No Puppet module parser is installed and no cache of the file /usr/share/foreman-installer/modules/foreman/manifests/compute/rackspace.pp' is available

Issue

• Running the Satellite installation script gives the error output below:

  Traceback (most recent call last):
      20: from /sbin/satellite-installer:8:in `<main>'
      19: from /opt/theforeman/tfm/root/usr/share/gems/gems/kafo-6.2.1/lib/kafo/kafo_configure.rb:50:in `run'
      18: from /opt/theforeman/tfm/root/usr/share/gems/gems/clamp-1.1.2/lib/clamp/command.rb:132:in `run'
      17: from /opt/theforeman/tfm/root/usr/share/gems/gems/clamp-1.1.2/lib/clamp/command.rb:132:in `new'
      16: from /opt/theforeman/tfm/root/usr/share/gems/gems/kafo-6.2.1/lib/kafo/kafo_configure.rb:140:in `initialize'
      15: from /opt/theforeman/tfm/root/usr/share/gems/gems/kafo-6.2.1/lib/kafo/hooking.rb:56:in `execute'
      14: from /opt/theforeman/tfm/root/usr/share/gems/gems/kafo-6.2.1/lib/kafo/hooking.rb:56:in `each'
      13: from /opt/theforeman/tfm/root/usr/share/gems/gems/kafo-6.2.1/lib/kafo/hooking.rb:58:in `block in execute'
      12: from /opt/theforeman/tfm/root/usr/share/gems/gems/kafo-6.2.1/lib/kafo/hook_context.rb:19:in `execute'
      11: from /opt/theforeman/tfm/root/usr/share/gems/gems/kafo-6.2.1/lib/kafo/hook_context.rb:19:in `instance_eval'
      10: from /opt/theforeman/tfm/root/usr/share/gems/gems/kafo-6.2.1/lib/kafo/hooking.rb:35:in `block (4 levels) in load'
       9: from /opt/theforeman/tfm/root/usr/share/gems/gems/kafo-6.2.1/lib/kafo/hooking.rb:35:in `instance_eval'
       8: from /usr/share/foreman-installer/hooks/boot/12-clear_pulp_content.rb:1:in `block (4 levels) in load'
       7: from /usr/share/foreman-installer/hooks/boot/01-kafo-hook-extensions.rb:85:in `pulp_present?'
       6: from /opt/theforeman/tfm/root/usr/share/gems/gems/kafo-6.2.1/lib/kafo/hook_context.rb:113:in `module_present?'
       5: from /opt/theforeman/tfm/root/usr/share/gems/gems/kafo-6.2.1/lib/kafo/kafo_configure.rb:246:in `module'
       4: from /opt/theforeman/tfm/root/usr/share/gems/gems/kafo-6.2.1/lib/kafo/kafo_configure.rb:242:in `modules'
       3: from /opt/theforeman/tfm/root/usr/share/gems/gems/kafo-6.2.1/lib/kafo/configuration.rb:132:in `modules'
       2: from /opt/theforeman/tfm/root/usr/share/gems/gems/kafo-6.2.1/lib/kafo/configuration.rb:132:in `map'
       1: from /opt/theforeman/tfm/root/usr/share/gems/gems/kafo-6.2.1/lib/kafo/configuration.rb:132:in `block in modules'
  /opt/theforeman/tfm/root/usr/share/gems/gems/kafo-6.2.1/lib/kafo/puppet_module.rb:69:in `parse': No Puppet module parser is installed and no cache of the file /usr/share/foreman-installer/modules/foreman/manifests/compute/rackspace.pp is available. Please check debug logs and install optional dependencies for the parser. (Kafo::ParserError)