Run nixpkgs-fmt .

https://github.com/nix-community/nixpkgs-fmt

ci.nix

@@ -9,12 +9,10 @@
 # then your CI will be able to build and cache only those packages for
 # which this is possible.
 
-{ pkgs ? import <nixpkgs> {} }:
+{ pkgs ? import <nixpkgs> { } }:
 
 with builtins;
-
 let
-
   isReserved = n: n == "lib" || n == "overlays" || n == "modules";
   isDerivation = p: isAttrs p && p ? type && p.type == "derivation";
   isBuildable = p: !(p.meta.broken or false) && p.meta.license.free or true;
@@ -29,10 +27,10 @@ let
     let
       f = p:
         if shouldRecurseForDerivations p then flattenPkgs p
-        else if isDerivation p then [p]
-        else [];
+        else if isDerivation p then [ p ]
+        else [ ];
     in
-      concatMap f (attrValues s);
+    concatMap f (attrValues s);
 
   outputsOf = p: map (o: p.${o}) p.outputs;
 
@@ -40,13 +38,12 @@ let
 
   nurPkgs =
     flattenPkgs
-    (listToAttrs
-    (map (n: nameValuePair n nurAttrs.${n})
-    (filter (n: !isReserved n)
-    (attrNames nurAttrs))));
+      (listToAttrs
+        (map (n: nameValuePair n nurAttrs.${n})
+          (filter (n: !isReserved n)
+            (attrNames nurAttrs))));
 
 in
-
 rec {
   buildPkgs = filter isBuildable nurPkgs;
   cachePkgs = filter isCacheable buildPkgs;

default.nix

@@ -6,7 +6,7 @@
 # commands such as:
 #     nix-build -A mypackage
 
-{ pkgs ? import <nixpkgs> {} }:
+{ pkgs ? import <nixpkgs> { } }:
 
 {
   # The `lib`, `modules`, and `overlay` names are special
@@ -18,4 +18,3 @@
   # some-qt5-package = pkgs.libsForQt5.callPackage ./pkgs/some-qt5-package { };
   # ...
 }
-

lib/default.nix

@@ -5,4 +5,3 @@ with pkgs.lib; {
   #
   # hexint = x: hexvals.${toLower x};
 }
-

modules/default.nix

@@ -3,4 +3,3 @@
   #
   # my-module = ./my-module;
 }
-

overlay.nix

@@ -3,16 +3,13 @@
 # configuration.
 
 self: super:
-
 let
-
   isReserved = n: n == "lib" || n == "overlays" || n == "modules";
   nameValuePair = n: v: { name = n; value = v; };
   nurAttrs = import ./default.nix { pkgs = super; };
 
 in
-
-  builtins.listToAttrs
+builtins.listToAttrs
   (map (n: nameValuePair n nurAttrs.${n})
-  (builtins.filter (n: !isReserved n)
-  (builtins.attrNames nurAttrs)))
+    (builtins.filter (n: !isReserved n)
+      (builtins.attrNames nurAttrs)))

overlays/default.nix

@@ -3,4 +3,3 @@
   #
   # my-overlay = import ./my-overlay;
 }
-

pkgs/example-package/default.nix

@@ -7,4 +7,3 @@ stdenv.mkDerivation rec {
   buildPhase = "echo echo Hello World > example";
   installPhase = "install -Dm755 example $out";
 }
-