impure.nix: add new pseudohosts: baseline-{aarch64,x86_64}

immediately apparent is that the config takes 4x as long to eval on cross than on native, regardless of anything else

hosts/common/fs.nix

@@ -75,7 +75,7 @@ let
     ];
   };
 
-  ifSshAuthorized = lib.mkIf config.sane.hosts.by-name."${config.networking.hostName}".ssh.authorized;
+  ifSshAuthorized = lib.mkIf (((config.sane.hosts.by-name."${config.networking.hostName}" or {}).ssh or {}).authorized or false);
 
   remoteHome = name: { host ? name }: let
     mountpoint = "/mnt/${name}/home";

hosts/instantiate.nix

@@ -8,9 +8,10 @@
 
 {
   imports = [
-    ./by-name/${hostName}
     ./common
     ./modules
+  ] ++ lib.optionals (builtins.pathExists ./by-name/${hostName}) [
+    ./by-name/${hostName}
   ];
 
   networking.hostName = hostName;

impure.nix

@@ -48,12 +48,17 @@ let
   };
 
   hosts = lib.foldl' (acc: host: acc // mkHost host) {} [
+    # real hosts:
     { name = "crappy"; system = "armv7l-linux";  }
     { name = "desko";  system = "x86_64-linux";  }
     { name = "lappy";  system = "x86_64-linux";  }
     { name = "moby";   system = "aarch64-linux"; }
-    { name = "rescue"; system = "x86_64-linux";  }
     { name = "servo";  system = "x86_64-linux";  }
+
+    { name = "rescue"; system = "x86_64-linux";  }
+    # pseudo hosts used for debugging
+    { name = "baseline-x86_64";  system = "x86_64-linux";  }
+    { name = "baseline-aarch64";  system = "aarch64-linux";  }
   ];
 
   pkgs = mkPkgs {};