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:
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.