Proper way of adding Qt5 patch to Nixpkgs

I’d like to add/modify a patch in Nixpkgs for qtbase to address #76080. The readme in pkgs/development/libraries/qt-5 has these instructions for patches:

However the linked repository for qtbase only goes up to nixpkgs/5.9.


Has something about this process changed without an update to the documentation? What’s the proper way of submitting patches for Qt5?

in your screenshot you can see 5.10?

But no nixpkgs/5.10 like the instructions ask for. Also, Qt 5.10 isn’t even packaged in Nixpkgs anymore, the lowest version there is 5.12.

There are some pages where you could check (besides git and hydra).

I don’t want to patch a dropped version of Qt5, I want to patch what’s still in Nixpkgs. I see no point in submitting a patch for 5.9 or 5.10, unless the current workflow for adding a qtbase 5.15 patch is to somehow base it on 5.9 & rebase against upstream 5.15, which seems very wrong and definitely undocumented to me.