macos/system: add shells

system/macos/system.nix

@@ -95,6 +95,9 @@
   # Custom user preferences (these require logout/login to take effect)
   system.startup.chime = false;            # Disable startup sound
 
+  # Manage /etc/shells and place add nix version of bash
+  environment.shells = [ pkgs.bash ];
+
   system.activationScripts.postActivation.text = ''
     # Following line should allow us to avoid a logout/login cycle when changing settings
     sudo -u ${config.system.primaryUser} /System/Library/PrivateFrameworks/SystemAdministration.framework/Resources/activateSettings -u