Add coreutils to PATH of main script also.

home-manager/default.nix

@@ -28,6 +28,7 @@ pkgs.stdenv.mkDerivation {
 
     substituteInPlace $out/bin/home-manager \
       --subst-var-by bash "${pkgs.bash}" \
+      --subst-var-by coreutils "${pkgs.coreutils}" \
       --subst-var-by MODULES_PATH '${modulesPath}' \
       --subst-var-by HOME_MANAGER_EXPR_PATH "${homeManagerExpr}"
   '';

home-manager/home-manager

@@ -1,5 +1,7 @@
 #!@bash@/bin/bash
 
+PATH=@coreutils@/bin:$PATH
+
 set -euo pipefail
 
 function doBuild() {