diff --git a/modules/common/shell/0_nushell.nix b/modules/common/shell/0_nushell.nix
index 0226b61..f96211a 100644
--- a/modules/common/shell/0_nushell.nix
+++ b/modules/common/shell/0_nushell.nix
@@ -1,60 +1,17 @@
 { config, lib, pkgs, ... }: let
-  inherit (lib) attrNames attrValues concatStringsSep const enabled filter filterAttrs flatten foldl' head last listToAttrs mapAttrs mapAttrsToList match nameValuePair readFile replaceStrings splitString;
+  inherit (lib) attrNames attrValues const enabled filterAttrs mapAttrs readFile replaceStrings;
 
   package = pkgs.nushell;
 in {
-  shells."0" = package;
-
   home-manager.sharedModules = [(homeArgs: let
     config' = homeArgs.config;
 
-    environmentVariables = let
-      variablesMap = {
-        HOME = config'.home.homeDirectory;
-        USER = config'.home.username;
-
-        XDG_CACHE_HOME  = config'.xdg.cacheHome;
-        XDG_CONFIG_HOME = config'.xdg.configHome;
-        XDG_DATA_HOME   = config'.xdg.dataHome;
-        XDG_STATE_HOME  = config'.xdg.stateHome;
-      }
-      |> mapAttrsToList (name: value: [
-        { name = "\$${name}"; inherit value; }
-        { name = "\${${name}}"; inherit value; }
-      ])
-      |> flatten
-      |> listToAttrs;
-
-      environmentVariables = config.environment.variables;
-
-      homeVariables = config'.home.sessionVariables;
-
-      homeVariablesExtra = pkgs.runCommand "home-variables-extra.env" {} ''
-          bash -ic '
-            ${variablesMap
-            |> mapAttrsToList (name: value: "export ${name}='${value}'")
-            |> concatStringsSep "\n"}
-
-            alias export=echo
-            source ${config'.home.sessionVariablesPackage}/etc/profile.d/hm-session-vars.sh
-          ' > $out
-        ''
-        |> readFile
-        |> splitString "\n"
-        |> filter (s: s != "")
-        |> map (match "([^=]+)=(.*)")
-        |> map (keyAndValue: nameValuePair (head keyAndValue) (last keyAndValue))
-        |> foldl' (x: y: x // y) {};
-
-      homeSearchVariables = config'.home.sessionSearchVariables
-        |> mapAttrs (const <| concatStringsSep ":");
-    in environmentVariables
-    // homeVariables
-    // homeVariablesExtra
-    // homeSearchVariables
-    |> mapAttrs (const <| replaceStrings (attrNames variablesMap) (attrValues variablesMap))
+    environmentVariables = config.environment.variables
+    |> mapAttrs (const <| replaceStrings (attrNames config'.variablesMap) (attrValues config'.variablesMap))
     |> filterAttrs (name: const <| name != "TERM");
   in {
+    shells."0" = package;
+
     programs.nushell = enabled {
       inherit package;
 
diff --git a/modules/common/shell/default.nix b/modules/common/shell/default.nix
index a22401e..9f68be9 100644
--- a/modules/common/shell/default.nix
+++ b/modules/common/shell/default.nix
@@ -1,16 +1,78 @@
-{ config, lib, ... }: let
-  inherit (lib) attrsToList catAttrs mkConst mkIf mkValue sortOn toInt;
+{ config, lib, pkgs, ... }: let
+  inherit (lib) attrsToList catAttrs concatStringsSep const filter flatten foldl' getAttr getExe head last listToAttrs mapAttrs mapAttrsToList match mkConst mkIf mkValue nameValuePair readFile sortOn splitString toInt unique;
 in {
-  options.shells = mkValue {};
+  environment.shells = config.home-manager.users
+  |> mapAttrsToList (const <| getAttr "shellsByPriority")
+  |> flatten
+  |> unique;
 
-  options.shellsByPriority = mkConst (config.shells
-    |> attrsToList
-    |> sortOn ({ name, ... }: toInt name)
-    |> catAttrs "value");
+  home-manager.sharedModules = [
 
-  config = mkIf config.isDarwin {
-    environment.shells = config.shellsByPriority;
-  };
+  (homeArgs: let
+    config' = homeArgs.config;
+  in {
+    options.shells = mkValue {};
+
+    options.shellsByPriority = mkConst (config'.shells
+      |> attrsToList
+      |> sortOn ({ name, ... }: toInt name)
+      |> catAttrs "value");
+
+    options.variablesMap = mkConst ({
+      HOME = config'.home.homeDirectory;
+      USER = config'.home.username;
+
+      XDG_CACHE_HOME  = config'.xdg.cacheHome;
+      XDG_CONFIG_HOME = config'.xdg.configHome;
+      XDG_DATA_HOME   = config'.xdg.dataHome;
+      XDG_STATE_HOME  = config'.xdg.stateHome;
+    }
+    |> mapAttrsToList (name: value: [
+      { name = "\$${name}"; inherit value; }
+      { name = "\${${name}}"; inherit value; }
+    ])
+    |> flatten
+    |> listToAttrs);
+  })
+
+  (mkIf config.isDarwin (homeArgs: let
+    config' = homeArgs.config;
+
+    homeSessionVariables = let
+      homeSessionVariables = config'.home.sessionVariables;
+
+      homeSessionVariablesExtra = pkgs.runCommand "home-variables-extra.env" {} ''
+          bash -ic '
+            ${config'.variablesMap
+            |> mapAttrsToList (name: value: "export ${name}='${value}'")
+            |> concatStringsSep "\n"}
+
+            alias export=echo
+            source ${config'.home.sessionVariablesPackage}/etc/profile.d/hm-session-vars.sh
+          ' > $out
+        ''
+        |> readFile
+        |> splitString "\n"
+        |> filter (s: s != "")
+        |> map (match "([^=]+)=(.*)")
+        |> map (keyAndValue: nameValuePair (head keyAndValue) (last keyAndValue))
+        |> foldl' (x: y: x // y) {};
+
+      homeSessionSearchVariables = config'.home.sessionSearchVariables
+        |> mapAttrs (const <| concatStringsSep ":");
+    in homeSessionVariables
+    // homeSessionVariablesExtra
+    // homeSessionSearchVariables;
+  in {
+    home.file.".zshrc".text = mkIf config.isDarwin /* zsh */ ''
+      ${homeSessionVariables
+      |> mapAttrsToList (name: value: "export ${name}='${value}'")
+      |> concatStringsSep "\n"}
+      SHELL='${getExe <| head config'.shellsByPriority}' exec "$SHELL"
+    '';
+  }))
+
+  ];
 
   # More at modules/linux/shell/default.nix.
   #
diff --git a/modules/common/shell/shadow-xcode.nix b/modules/common/shell/shadow-xcode.nix
new file mode 100644
index 0000000..e66f932
--- /dev/null
+++ b/modules/common/shell/shadow-xcode.nix
@@ -0,0 +1,78 @@
+{ config, lib, pkgs, ... }: let
+  inherit (lib) getExe mkAfter mkIf;
+in {
+  home-manager.sharedModules = mkIf config.isDarwin [(homeArgs: let
+    config' = homeArgs.config;
+    lib' = homeArgs.lib;
+
+    inherit (lib'.hm.dag) entryAfter;
+
+    # Replace with the command that has been triggering
+    # the "install developer tools" popup.
+    #
+    # Set by default to "SplitForks" because who even uses that?
+    originalTrigger = "/usr/bin/SplitForks";
+    originalTriggerLiteral = ''"${originalTrigger}"'';
+
+    # Where the symbolic links to `/usr/bin/false` will
+    # be created in to shadow all popup-triggering binaries.
+    #
+    # Place this in your $env.PATH right before /usr/bin
+    # to never get the "install developer tools" popup ever again:
+    #
+    # ```nu
+    # let usr_bin_index = $env.PATH
+    # | enumerate
+    # | where item == /usr/bin
+    # | get 0.index
+    #
+    # $env.PATH = $env.PATH | insert $usr_bin_index $shadow_path
+    # ```
+    #
+    # Do NOT set this to a path that you use for other things,
+    # it will get deleted if it exists to only have the shadowers.
+    shadowPath = "${config'.home.homeDirectory}/.local/shadow"; # Did you read the comment?
+    shadowPathLiteral = ''"${shadowPath}"'';
+  in {
+    home.activation.shadow = entryAfter [ "installPackages" "linkGeneration" ] /* bash */ ''
+      ${getExe pkgs.nushell} ${pkgs.writeScript "shadow-xcode.nu" ''
+        use std null_device
+
+        let original_size = ls ${originalTriggerLiteral} | get 0.size
+
+        let shadoweds = ls /usr/bin
+        | flatten
+        | where {
+          # All xcode-select binaries are the same size, so we can narrow down and not run weird stuff.
+          $in.size == $original_size and (try {
+            open $null_device | ^$in.name out+err>| str contains "xcode-select: note: No developer tools were found, requesting install."
+          } catch {
+            # If it exited with a nonzero code, it's probably already set up.
+            false
+          })
+        }
+        | get name
+        | each { path basename }
+
+        rm -rf ${shadowPathLiteral}
+        mkdir ${shadowPathLiteral}
+
+        for shadowed in $shadoweds {
+          ln --symbolic /usr/bin/false (${shadowPathLiteral} | path join $shadowed)
+        }
+      ''}
+    '';
+
+    programs.nushell.configFile.text = mkAfter /* nu */ ''
+      do --env {
+        let usr_bin_index = $env.PATH
+        | enumerate
+        | where item == /usr/bin
+        | get 0.index;
+
+        $env.PATH = $env.PATH
+        | insert $usr_bin_index ${shadowPathLiteral};
+      }
+    '';
+  })];
+}
diff --git a/modules/linux/shell/default.nix b/modules/linux/shell/default.nix
index dff21fa..56eed90 100644
--- a/modules/linux/shell/default.nix
+++ b/modules/linux/shell/default.nix
@@ -1,9 +1,15 @@
 { config, lib, pkgs, ... }: let
-  inherit (lib) concatStringsSep;
+  inherit (lib) concatStringsSep const flatten getAttr mapAttrsToList unique;
 in {
   users.defaultUserShell = pkgs.crash;
 
-  environment.sessionVariables.SHELLS = config.shellsByPriority
-    |> map (drv: "${drv}${drv.shellPath}")
-    |> concatStringsSep ":";
+  # TODO: This should be a per-user session variable. But we can't set
+  # a home-manager session variable because that's initialized by the
+  # shell itself! Lol.
+  environment.sessionVariables.SHELLS = config.home-manager.users
+  |> mapAttrsToList (const <| getAttr "shellsByPriority")
+  |> flatten
+  |> map (drv: "${drv}${drv.shellPath}")
+  |> unique
+  |> concatStringsSep ":";
 }
diff --git a/rebuild.nu b/rebuild.nu
index 1578e88..deda31e 100755
--- a/rebuild.nu
+++ b/rebuild.nu
@@ -57,77 +57,7 @@ def main --wrapped [
 
   if (uname | get kernel-name) == "Darwin" {
     NH_BYPASS_ROOT_CHECK=true NH_NO_CHECKS=true nh darwin switch . ...$nh_flags -- ...$nix_flags
-
-    if not (xcode-select --install e>| str contains "Command line tools are already installed") {
-      darwin-shadow-xcode-popup
-    }
-
-    darwin-set-zshrc
   } else {
     NH_BYPASS_ROOT_CHECK=true NH_NO_CHECKS=true nh os switch . ...$nh_flags -- ...$nix_flags
   }
 }
-
-# Replace with the command that has been triggering
-# the "install developer tools" popup.
-#
-# Set by default to "SplitForks" because who even uses that?
-const original_trigger = "/usr/bin/SplitForks"
-
-# Where the symbolic links to `/usr/bin/false` will
-# be created in to shadow all popup-triggering binaries.
-#
-# Place this in your $env.PATH right before /usr/bin
-# to never get the "install developer tools" popup ever again:
-#
-# ```nu
-# let usr_bin_index = $env.PATH
-# | enumerate
-# | where item == /usr/bin
-# | get 0.index
-#
-# $env.PATH = $env.PATH | insert $usr_bin_index $shadow_path
-# ```
-#
-# Do NOT set this to a path that you use for other things,
-# it will get deleted if it exists to only have the shadowers.
-const shadow_path = "~/.local/shadow" | path expand # Did you read the comment?
-
-def darwin-shadow-xcode-popup [] {
-  print "shadowing xcode popup binaries..."
-
-  let original_size = ls $original_trigger | get 0.size
-
-  let shadoweds = ls /usr/bin
-  | flatten
-  | where {
-    # All xcode-select binaries are the same size, so we can narrow down and not run weird stuff.
-    $in.size == $original_size
-  }
-  | where {
-    ^$in.name e>| str contains "xcode-select: note: No developer tools were found, requesting install."
-  }
-  | get name
-  | each { path basename }
-
-  rm -rf $shadow_path
-  mkdir $shadow_path
-
-  for shadowed in $shadoweds {
-    let shadow_path = $shadow_path | path join $shadowed
-
-    ln --symbolic /usr/bin/false $shadow_path
-  }
-}
-
-def darwin-set-zshrc [] {
-  print "setting zshrc..."
-
-  let nu_command = $"let usr_bin_index = $env.PATH | enumerate | where item == /usr/bin | get 0.index;
-$env.PATH = $env.PATH | insert $usr_bin_index ($shadow_path | path expand);
-$env.SHELL = which nu | get 0.path" | str replace --all "\n" ""
-
-  let zshrc = $"exec nu --execute '($nu_command)'"
-
-  $zshrc | save --force ~/.zshrc
-}