xorg-silence-aliases

Overlays

A nixpkgs overlay that silences the eval-time deprecation warnings emitted for legacy pkgs.xorg.<name> accesses — without changing which derivation you get.

The problem

nixpkgs has, over many releases, been promoting packages out of the xorg scope up to the top level: xorg.xrandr became xrandr, xorg.setxkbmap became setxkbmap, and so on. To stay backward-compatible, nixpkgs keeps the old xorg.<name> attribute alive — but wraps it in a builtins.trace deprecation warning. So every time anything in your config still reaches for the old spelling (your own modules, or third-party modules you import), you get a wall of:

trace: warning: `xorg.xrandr` is deprecated, use `xrandr` instead.

printed on every evaluation — nixos-rebuild, nix build, nix flake check, CI. It's pure noise: the two spellings already resolve to the same package. But it drowns out warnings you actually care about.

The insight / trap

You can't easily fix every call site (some live in packages you don't own), and you don't want to drop the old attribute (that would break the call sites outright). The fix is to re-alias each promoted name back onto xorg, but point it at the promoted top-level derivation — so the old spelling stops being the deprecated wrapper and becomes a plain reference to the same package. Both xorg.xrandr and xrandr then resolve to one identical derivation, and the warning is gone.

Two subtleties this recipe bakes in:

1. Use final (self), not prev, on the right-hand side. final.xrandr is the fully-overlaid value, so the alias tracks any later overlay that replaces the top-level package. Aliasing to prev.xrandr would pin the old spelling to the pre-overlay derivation and silently desync the two names.

2. Only alias names that actually exist at the top level. Which names have been promoted varies by nixpkgs version. Blindly writing xorg.foo = final.foo breaks the day foo isn't a top-level attribute on your channel. This overlay filters the candidate list through lib.hasAttr name final, so unpromoted names are left untouched and the overlay stays a safe drop-in across channels.

Usage

Plain overlay list:

nixpkgs.overlays = [ (import ./overlays/xorg-silence-aliases) ];

As a flake output:

overlays.default = import ./overlays/xorg-silence-aliases;

There are no options to configure — import it and the noise is gone.

Caveats

• This only silences the xorg-scope promotions. Other unrelated nixpkgs deprecation warnings are untouched (by design).
• If a future nixpkgs warns about a name not in promotedNames, add it to the list in default.nix; the hasAttr filter makes extra entries harmless.
• It changes nothing about what you build — the derivations are byte-identical before and after. It only removes the trace output.

Source

overlays/xorg-silence-aliases/default.nix

# xorg-silence-aliases
#
# A nixpkgs overlay that silences the eval-time deprecation warnings emitted for
# legacy `pkgs.xorg.<name>` accesses.
#
# nixpkgs keeps promoting packages out of the `xorg` package scope up to the
# top level (e.g. `xorg.xrandr` -> `xrandr`). Each legacy access to the old
# `xorg.<name>` spelling then trips a `builtins.trace` deprecation warning at
# evaluation time. This overlay re-points every promoted name back onto the
# `xorg` attrset so BOTH spellings resolve to the *same* derivation and the
# warning disappears.
#
# Usage:
#   nixpkgs.overlays = [ (import ./xorg-silence-aliases) ];
# or as a flake overlay:
#   overlays.default = import ./overlays/xorg-silence-aliases;
#
# The list below is the set of names that have (at various nixpkgs versions)
# been promoted out of `xorg`. Rather than hardcode `xorg.foo = final.foo` for
# each — which would break the day a name is *not* present at the top level on
# your channel — we alias only the names that actually exist as a top-level
# attribute of `final`. That keeps the overlay a safe drop-in across channels:
# names that have not been promoted (yet, or on your pin) are simply left alone.
#
# `final` (a.k.a. `self`) is used for the right-hand sides on purpose: it is the
# fully-overlaid package set, so the alias tracks any *later* overlay that
# replaces the top-level derivation. Using `prev` here would pin the alias to
# the pre-overlay value and could desync the two spellings.

final: prev:

let
  # Names that have been (or may be) promoted out of the `xorg` scope to the
  # top level. Extend this list if your channel warns about a name not covered.
  promotedNames = [
    "appres"
    "bdftopcf"
    "bitmap"
    "editres"
    "fonttosfnt"
    "gccmakedep"
    "iceauth"
    "ico"
    "imake"
    "libdmx"
    "libfontenc"
    "libpciaccess"
    "libxcb"
    "libxcvt"
    "libxkbfile"
    "libxshmfence"
    "listres"
    "lndir"
    "luit"
    "makedepend"
    "mkfontscale"
    "oclock"
    "pixman"
    "sessreg"
    "setxkbmap"
    "smproxy"
    "transset"
    "viewres"
    "wrapWithXFileSearchPathHook"
    "x11perf"
    "xauth"
    "xbacklight"
    "xbitmaps"
    "xcalc"
    "xclock"
    "xcmsdb"
    "xcompmgr"
    "xconsole"
    "xcursorgen"
    "xdm"
    "xdpyinfo"
    "xdriinfo"
    "xev"
    "xeyes"
    "xfd"
    "xfontsel"
    "xfs"
    "xfsinfo"
    "xgamma"
    "xgc"
    "xhost"
    "xinit"
    "xinput"
    "xkbcomp"
    "xkbevd"
    "xkbprint"
    "xkbutils"
    "xkill"
    "xload"
    "xlsatoms"
    "xlsclients"
    "xlsfonts"
    "xmag"
    "xmessage"
    "xmodmap"
    "xmore"
    "xorgproto"
    "xpr"
    "xprop"
    "xrandr"
    "xrdb"
    "xrefresh"
    "xset"
    "xsetroot"
    "xsm"
    "xstdcmap"
    "xtrans"
    "xvfb"
    "xvinfo"
    "xwd"
    "xwininfo"
    "xwud"
  ];

  lib = prev.lib;

  # Keep only names that are actually present at the top level of the overlaid
  # set, and map each to its promoted top-level derivation.
  aliases = lib.genAttrs
    (lib.filter (name: lib.hasAttr name final) promotedNames)
    (name: final.${name});
in
{
  xorg = prev.xorg // aliases;
}