Merge pull request #132047 from Mic92/build-fhs-userenv

build-fhs-userenv: fix defaults on aarch64

pkgs/build-support/build-fhs-userenv/env.nix

@@ -1,8 +1,11 @@
 { stdenv, buildEnv, writeText, pkgs, pkgsi686Linux }:
 
-{ name, profile ? ""
-, targetPkgs ? pkgs: [], multiPkgs ? pkgs: []
-, extraBuildCommands ? "", extraBuildCommandsMulti ? ""
+{ name
+, profile ? ""
+, targetPkgs ? pkgs: []
+, multiPkgs ? pkgs: []
+, extraBuildCommands ? ""
+, extraBuildCommandsMulti ? ""
 , extraOutputsToInstall ? []
 }:
 
@@ -23,7 +26,8 @@
 
 let
   is64Bit = stdenv.hostPlatform.parsed.cpu.bits == 64;
-  isMultiBuild  = multiPkgs != null && is64Bit;
+  # multi-lib glibc is only supported on x86_64
+  isMultiBuild  = multiPkgs != null && stdenv.hostPlatform.system == "x86_64-linux";
   isTargetBuild = !isMultiBuild;
 
   # list of packages (usually programs) which are only be installed for the