nsncd: init at unstable-2021-10-20

This is currently pointing to a custom branch that contains the missing
request types from https://github.com/twosigma/nsncd/issues/37, as well
as Type=notify support.

pkgs/os-specific/linux/nsncd/default.nix

@@ -0,0 +1,30 @@
+{ lib
+, stdenv
+, fetchFromGitHub
+, rustPlatform
+, nix-gitignore
+}:
+
+rustPlatform.buildRustPackage rec {
+  pname = "nsncd";
+  version = "unstable-2021-10-20";
+
+  src = fetchFromGitHub {
+    owner = "nix-community";
+    repo = "nsncd";
+    rev = "b9425070bb308565a6e4dc5aefd568952a07a4ed";
+    hash = "sha256-ZjInzPJo+PWAM2gAKhlasLXiqo+2Df4DIXpNwtqQVc8=";
+  };
+
+  cargoSha256 = "sha256-hxdI+HHB0PB/zDMI21Pg5Xr9mTDn4T+OcAAenUox4bs=";
+
+  meta = with lib; {
+    description = "the name service non-caching daemon";
+    longDescription = ''
+      nsncd is a nscd-compatible daemon that proxies lookups, without caching.
+    '';
+    homepage = "https://github.com/twosigma/nsncd";
+    license = licenses.asl20;
+    maintainers = with maintainers; [ flokli ninjatrappeur ];
+  };
+}

pkgs/top-level/all-packages.nix

@@ -36594,6 +36594,8 @@ with pkgs;
 
   nhentai = callPackage ../applications/misc/nhentai { };
 
+  nsncd = callPackage ../os-specific/linux/nsncd { };
+
   nvd = callPackage ../tools/package-management/nvd { };
 
   solfege = python3Packages.callPackage ../misc/solfege { };