Add state version

diff --git a/nixops/eldiron.nix b/nixops/eldiron.nix
index d6915c291076ad1238a6f70c03b644f0d5bb6665..8dc8c4d8273a8e09e624fc26e64d51f403f9a460 100644 (file)
--- a/nixops/eldiron.nix
+++ b/nixops/eldiron.nix
@@ -107,5 +107,11 @@
         ''
       ];
     };
+
+    # This value determines the NixOS release with which your system is
+    # to be compatible, in order to avoid breaking some software such as
+    # database servers. You should change this only after NixOS release
+    # notes say you should.
+    system.stateVersion = "18.09"; # Did you read the comment?
   };
 }