Guix has had support for external package definitions for a long time (via GUIX_PACKAGE_PATH) and recently gained a channels feature, which makes this even easi

Guix has had support for external package definitions for a long time (via GUIX_PACKAGE_PATH) and recently gained a channels feature, which makes this even easier. At the institute where I work we use this feature to provide package variants that aren't going to be added to Guix proper (e.g. because they are no longer supported upstream or because they are only useful on obscure systems). This mechanism can be used to include package definitions for non-free software, of course, but this doesn't mean that the Guix project encourages the use of non-free software. You have the freedom to package up and use non-free software, but we won't make them part of Guix, build them on our build farms, and we won't hold back changes to the mechanism even if that might break 3rd-party collections of non-free software. You don't really need a blog post about how to set up a package repository, because it's right there in the Guix manual. PS: It's "Guix", not "GUIX" ;)