The PR documents a pattern like this
(final: prev: {
pythonPackagesOverlays = prev.pythonPackagesOverlays ++ [
(
python-final: python-prev: {
foo = ...;
}
)
];
})
but that same commit introduces numerous changes to various files in the nixpkgs infrastructure, from which I infer that the documented approach depends on those changes. As the PR has not been merged, it would seem that this approach is not going to work in a current nixpkgs. What have I misunderstood?