This commit:
https://github.com/theforeman/foreman/commit/e42aa400f4a03450520b87bf6ea200bc101af740#diff-f931fc066ae7973420792a69ab1fbfcbL5

appears to have broken discovery in nightly:

as that constant is used here: https://github.com/theforeman/foreman/commit/e42aa400f4a03450520b87bf6ea200bc101af740#diff-f931fc066ae7973420792a69ab1fbfcbL5

We noticed this in katello on installation:

/opt/rh/ruby193/root/usr/share/gems/gems/foreman_hooks-0.3.7/lib/foreman_hooks.rb:83:in `load_missing_constant_with_hooks': uninitialized constant Net::Validations::MAC_REGEXP (NameError)
from /opt/rh/ruby193/root/usr/share/gems/gems/rake-0.9.2.2/lib/rake/ext/module.rb:36:in `const_missing'
from /opt/rh/ruby193/root/usr/share/gems/gems/foreman_discovery-1.3.0/app/models/host/discovered.rb:10:in `<class:Discovered>'
from /opt/rh/ruby193/root/usr/share/gems/gems/foreman_discovery-1.3.0/app/models/host/discovered.rb:3:in `<top (required)>'
from /opt/rh/ruby193/root/usr/share/rubygems/rubygems/custom_require.rb:36:in `require'
from /opt/rh/ruby193/root/usr/share/rubygems/rubygems/custom_require.rb:36:in `require'