coloursum: fix darwin build

pkgs/tools/text/coloursum/default.nix

@@ -1,4 +1,4 @@
-{ stdenv, fetchFromGitHub, rustPlatform }:
+{ stdenv, fetchFromGitHub, rustPlatform, Security }:
 
 rustPlatform.buildRustPackage rec {
   pname = "coloursum";
@@ -13,6 +13,8 @@ rustPlatform.buildRustPackage rec {
 
   cargoSha256 = "091flc5ymx0y43ld6bdmig5cy479b90bkmwv3yaysi5kpr28skvh";
 
+  buildInputs = stdenv.lib.optional stdenv.isDarwin Security;
+
   meta = with stdenv.lib; {
     description = "Colourise your checksum output";
     homepage = "https://github.com/ticky/coloursum";