Hi,
couldn’t find a better place for this report, let me know if there is one.
so currently for debian and ubuntu the debian packages share the same version (and package name) pattern (eg: chef_12.9.38-1_amd64.deb), which can cause problems when somebody(like me) try to mirror the same package for both ubuntu and debian in the same apt repository.
see https://www.aptly.info/doc/feature/duplicate/ for more details, but tl;dr: you shouldn’t provide two packages where the package version is the same, but the contents of the package file differs.
a simple solution could be to either add the distribution(debian, ubuntu) or the distribution release name (wheezy, trusty, jessie, xenial) to the package versions(this could be unfavorable as it seems that the same chef package tends to be supporting multiple distro release).