home-manager: fix use of `~` in paths

home/jez/home.nix

@@ -5,6 +5,7 @@ let
   util = import ./util.nix { inherit pkgs; };
   hostname = lib.strings.fileContents /etc/hostname;
   host-config = ./machines + "/${hostname}.nix";
+  h = "/home/jez";
 in
 {
   programs.home-manager.enable = true;
@@ -22,7 +23,7 @@ in
   };
 
   home.username = "jez";
-  home.homeDirectory = "/home/jez";
+  home.homeDirectory = h;
 
   home.stateVersion = "20.09";
 
@@ -64,18 +65,18 @@ in
     ];
 
   home.sessionVariables = {
-    WORKON_HOME = ~/.local/lib/languages/Python/virtualenvs;
-    RUSTUP_HOME = ~/.local/lib/languages/Rust/rustup;
-    CABAL_CONFIG = ~/.config/cabal/config;
-    CABAL_DIR = ~/.local/lib/languages/Haskell/cabal;
+    WORKON_HOME = "${h}/.local/lib/languages/Python/virtualenvs";
+    RUSTUP_HOME = "${h}/.local/lib/languages/Rust/rustup";
+    CABAL_CONFIG = "${h}/.config/cabal/config";
+    CABAL_DIR = "${h}/.local/lib/languages/Haskell/cabal";
 
-    PASSWORD_STORE_DIR = ~/Reference/Passwords;
+    PASSWORD_STORE_DIR = "${h}/Reference/Passwords";
     PASSWORD_STORE_KEY = "9E42CE071C4559D1";
 
     EDITOR = pkgs.vim + /bin/vim;
 
     TERMINFO_DIRS = lib.concatStringsSep ":" [
-      "~/.nix-profile/share/terminfo"
+      "${h}/.nix-profile/share/terminfo"
       ""
     ];
   };

home/jez/machines/erwin.nix

@@ -1,8 +1,9 @@
-{ pkgs, lib, ... }:
+{ pkgs, config, lib, ... }:
 
 with builtins;
 let
   nixGL = pkgs.callPackage (fetchTarball https://github.com/guibou/nixGL/archive/master.tar.gz) { inherit pkgs; };
+  h = config.home.homeDirectory;
 in
 {
 
@@ -10,7 +11,7 @@ in
 
   home.file = {
     ".pam_environment".text = ''
-      XDG_DATA_DIRS=${toString ~/.nix-profile/share}:/usr/local/share:/usr/share
+      XDG_DATA_DIRS=${h}/.nix-profile/share:/usr/local/share:/usr/share
     '';
 
     ".config/fontconfig/conf.d/10-nix-fonts.conf".text = ''
@@ -24,7 +25,7 @@ in
 
   services.mpd = {
     enable = true;
-    musicDirectory = ~/Music/Best;
+    musicDirectory = h + "/Music/Best";
     extraConfig = ''
       audio_output {
         type "pulse"

home/jez/machines/gwydion.nix

@@ -1,5 +1,8 @@
-{ pkgs, ... }:
+{ pkgs, config, ... }:
 
+let
+  h = config.home.homeDirectory;
+in
 {
   home.packages = with pkgs; [
     steam minecraft
@@ -7,7 +10,7 @@
 
   services.mpd = {
     enable = true;
-    musicDirectory = ~/Music/Best;
+    musicDirectory = h + "/Music/Best";
     network.listenAddress = "any";
     extraConfig = ''
       audio_output {