Running puppet resource package on Gentoo/Portage, currently only lists packages that were installed by puppet, but not those installed by hand.
This was introduced in https://github.com/puppetlabs/puppet/commit/9e7bf07580d79e5b68d28cc594162959cf2a8d7d.
Old line 79 contains a '\n'.
But, new line 123 does not.
So now, the result of eix is only a one liner, no matter how many packages are installed. Since further on, the provider reads eix output line by line, no "by hand"-installed package will be found.
I already opened a PR for this issue.
probability: low (gentoo)