Based on previous threads on centos-devel and some requests (including from Hyperscale SIG), we had a look at the best way to let some SIG build *against* EPEL for some needed Requires:/BuildRequires: dependencies

The first approach was to consider "importing" epel builds/pkgs into cbs, and let SIGs just "tag-build" in their own tag packages, that would also have permitted them to cherry-pick some versions and also ship these pkgs in their SIG repo if needed also a runtime instead of buildtime, but through some conversations, including with EPEL, we considered that it wasn't the best path.

Instead, what is now possible is the following : enabling Epel as externalrepo at *build* time so that if your SIG will *rely* on EPEL packages, you can already build against it and you can then ensure that users consuming pkgs from your SIG would have a dependency on epel itself (simple idea is to have your centos-release-$sig pkg having a Requires: on epel-release itself, already available in Extras)

The following EPEL repositories can be enabled (on demand) on CBS : - epel 7 (x86_64, ppc64le, aarch64) - epel 8 Everything (x86_64, ppc64le, aarch64) - epel Next 8 Everything (x86_64, ppc64le, aarch64)

Worth clarifying that we're talking about plain rpm pkgs, no modularity content at all. (and reminder CBS doesn't have a way to let you build any module -yet- either)

This was initially requested and tested/validated with the Hyperscale SIG through this RFE ticket : https://pagure.io/centos-infra/issue/306 , so if you want to "opt-in", feel free to also create ticket and we can enable these external repositories for your next builds

PS: just to clarify : if your SIG had to (re)build some EPEL packages for your own tags, nothing will change : you'll still have to rebuild EPEL upstream src.rpm into your tags to see these packages (built on cbs.centos.org koji) be signed and shipped out, without depending on any change (like ENVR bump) on upstream EPEL repositories

Kind Regards,