Error when enabling foreman provisioning

I am currently trying to choose a deployment tool for my homelab and while giving foreman a try I got stuck.

I have followed the quick start guide for foreman and it seems to be up and running. Now I wanted to enable provisioning by following the wizard. I am at step 3 of the wizard where it asks me to run the foreman installer on the command line. The same error pops up when provisioning with and without dhcp. The installer command looks something like this:

foreman-installer \ --enable-foreman-proxy \ --foreman-proxy-tftp=true \ --foreman-proxy-tftp-servername=192.168.1.2 \ --foreman-proxy-dhcp=true \ --foreman-proxy-dhcp-interface=eth0 \ --foreman-proxy-dhcp-gateway=192.168.1.1 \ --foreman-proxy-dhcp-range="192.168.1.30 192.168.1.60" \ --foreman-proxy-dhcp-nameservers="192.168.80.1" \ --foreman-proxy-dns=true \ --foreman-proxy-dns-interface=eth0 \ --foreman-proxy-dns-zone=internal.skelleton.net \ --foreman-proxy-dns-reverse=1.168.192.in-addr.arpa \ --foreman-proxy-dns-forwarders=192.168.1.1 \ --foreman-proxy-foreman-base-url=https://foreman.mynetwork.com \ --foreman-proxy-oauth-consumer-key=scretkey \ --foreman-proxy-oauth-consumer-secret=anotherkey 

It always gives me the following error:

 /usr/lib/ruby/vendor_ruby/kafo/configuration.rb:85:in `modules': undefined method `keys' for false:FalseClass (NoMethodError) from /usr/lib/ruby/vendor_ruby/kafo/kafo_configure.rb:173:in `modules' from /usr/lib/ruby/vendor_ruby/kafo/kafo_configure.rb:155:in `params' from /usr/lib/ruby/vendor_ruby/kafo/kafo_configure.rb:188:in `set_parameters' from /usr/lib/ruby/vendor_ruby/kafo/kafo_configure.rb:66:in `initialize' from /usr/lib/ruby/vendor_ruby/clamp/command.rb:133:in `new' from /usr/lib/ruby/vendor_ruby/clamp/command.rb:133:in `run' from /usr/lib/ruby/vendor_ruby/kafo/kafo_configure.rb:119:in `run' from /usr/sbin/foreman-installer:18:in `<main>' 

Since I never learned ruby I did not see what I was doing wrong just by looking at the file and google was not much help either. Did anyone here deal with an error like this already? My current guess is that I may be missing some dependency but with this information I don't really see which one that would be.

Edit: This is on Debian Jessie