pkgs: add lnd 0.15.4 (hotfix)

Includes an emergency hotfix:
https://github.com/lightningnetwork/lnd/releases/tag/v0.15.4-beta

pkgs/default.nix

@@ -37,5 +37,9 @@ let self = {
 
   pinned = import ./pinned.nix pkgs pkgsUnstable;
 
+  # TODO-EXTERNAL:
+  # Remove this when lnd 0.15.4 is available in the nixpkgs-unstable channel
+  lnd = pkgsUnstable.callPackage ./lnd-0.15.4.nix {};
+
   modulesPkgs = self // self.pinned;
 }; in self

pkgs/lnd-0.15.4.nix

@@ -0,0 +1,40 @@
+{ buildGoModule
+, fetchFromGitHub
+, lib
+, tags ? [ "autopilotrpc" "signrpc" "walletrpc" "chainrpc" "invoicesrpc" "watchtowerrpc" "routerrpc" "monitoring" "kvdb_postgres" "kvdb_etcd" ]
+}:
+
+buildGoModule rec {
+  pname = "lnd";
+  version = "0.15.4-beta";
+
+  src = fetchFromGitHub {
+    owner = "lightningnetwork";
+    repo = "lnd";
+    rev = "v${version}";
+    sha256 = "sha256-/PKW2Y6+PlWk88pC4DHFi1ZRqMfQzoO9MVLYZrB2UNc=";
+  };
+
+  vendorSha256 = "sha256-bUo0PhtOFhsZfhAXtRJMjfaLrAsOv3ksxsrPOlMNv48=";
+
+  subPackages = [ "cmd/lncli" "cmd/lnd" ];
+
+  preBuild = let
+    buildVars = {
+      RawTags = lib.concatStringsSep "," tags;
+      GoVersion = "$(go version | egrep -o 'go[0-9]+[.][^ ]*')";
+    };
+    buildVarsFlags = lib.concatStringsSep " " (lib.mapAttrsToList (k: v: "-X github.com/lightningnetwork/lnd/build.${k}=${v}") buildVars);
+  in
+  lib.optionalString (tags != []) ''
+    buildFlagsArray+=("-tags=${lib.concatStringsSep " " tags}")
+    buildFlagsArray+=("-ldflags=${buildVarsFlags}")
+  '';
+
+  meta = with lib; {
+    description = "Lightning Network Daemon";
+    homepage = "https://github.com/lightningnetwork/lnd";
+    license = licenses.mit;
+    maintainers = with maintainers; [ cypherpunk2140 prusnak ];
+  };
+}

pkgs/pinned.nix

@@ -6,7 +6,6 @@ pkgs: pkgsUnstable:
     bitcoind
     extra-container
     lightning-pool
-    lnd
     lndconnect;
 
   inherit (pkgsUnstable)