no stub: <insert TLC song>

This feature was introduced in
NixOS/nixpkgs#269551 and is mostly useful for
servers.

Saves around 80MiB of evaluation on x86_64 due to the extra i686 nixpkgs
instance.

nixos/common/default.nix

@@ -36,6 +36,10 @@
   # unecessary rebuilds.
   environment.noXlibs = false;
 
+  # Don't install the /lib/ld-linux.so.2 stub. This saves one instance of
+  # nixpkgs.
+  environment.ldso32 = null;
+
   # Ensure a clean & sparkling /tmp on fresh boots.
   boot.tmp.cleanOnBoot = lib.mkDefault true;
 }

nixos/server/default.nix

@@ -54,6 +54,10 @@
   # No mutable users by default
   users.mutableUsers = false;
 
+  # Don't install the /lib/ld-linux.so.2 and /lib64/ld-linux-x86-64.so.2
+  # stubs. Server users should know what they are doing.
+  environment.stub-ld.enable = false;
+
   systemd = {
     # Given that our systems are headless, emergency mode is useless.
     # We prefer the system to attempt to continue booting so