nix: add lwk and blockstream-electrs packages

restructure nixpkgs imports and package references.
The changes introduce two new packages
(`lwk` and `blockstream-electrs`).

packages.nix

@@ -1,32 +1,47 @@
 let
-# Pinning to revision f54322490f509985fa8be4ac9304f368bd8ab924 
-# - cln v24.02.1
-# - lnd v0.17.4-beta
-# - bitcoin v26.0
-# - elements v23.2.1
+    fetchNixpkgs = rev: fetchTarball "https://github.com/NixOS/nixpkgs/archive/${rev}.tar.gz";
+    # Pinning to revision f54322490f509985fa8be4ac9304f368bd8ab924 
+    # - cln v24.02.1
+    # - lnd v0.17.4-beta
+    # - bitcoin v26.0
+    # - elements v23.2.1
+    rev1 = "f54322490f509985fa8be4ac9304f368bd8ab924";
+    nixpkgs1 = fetchNixpkgs rev1;
+    pkgs1 = import nixpkgs1 {};
 
-rev = "f54322490f509985fa8be4ac9304f368bd8ab924";
-nixpkgs = fetchTarball "https://github.com/NixOS/nixpkgs/archive/${rev}.tar.gz";
-pkgs = import nixpkgs {};
+    # Override priority for bitcoin as /bin/bitcoin_test will
+    # confilict with /bin/bitcoin_test from elementsd.
+    bitcoind = (pkgs1.bitcoind.overrideAttrs (attrs: {
+        meta = attrs.meta or {} // {
+            priority = 0;
+        };
+    }));
+    # lwk: init at 0.3.0 #292522
+    # https://github.com/NixOS/nixpkgs/pull/292522/commits/2b3750792b2e4b52f472b6e6d88a6b02b6536c43
+    rev2 = "2b3750792b2e4b52f472b6e6d88a6b02b6536c43";
+    nixpkgs2 = fetchNixpkgs rev2;
+    pkgs2 = import nixpkgs2 {};
+    # blockstream-electrs: init at 0.4.1 #299761
+    # https://github.com/NixOS/nixpkgs/pull/299761/commits/680d27ad847801af781e0a99e4b87ed73965c69a
+    rev3 = "680d27ad847801af781e0a99e4b87ed73965c69a";
+    nixpkgs3 = fetchNixpkgs rev3;
+    pkgs3 = import nixpkgs3 {};
+    blockstream-electrs = pkgs3.blockstream-electrs.overrideAttrs (oldAttrs: {
+        cargoBuildFlags = [ "--features liquid" "--bin electrs" ];
+    });
 
-# Override priority for bitcoin as /bin/bitcoin_test will
-# confilict with /bin/bitcoin_test from elementsd.
-bitcoind = (pkgs.bitcoind.overrideAttrs (attrs: {
-    meta = attrs.meta or {} // {
-        priority = 0;
-    };
-}));
-
-in with pkgs;
+in
 {
     execs = {
-        clightning = clightning;
+        clightning = pkgs1.clightning;
         bitcoind = bitcoind;
-        elementsd = elementsd;
-        mermaid = nodePackages.mermaid-cli;
-        lnd = lnd;
-    };
-    testpkgs = [ go bitcoind elementsd lnd ];
-    devpkgs = [ go_1_22 gotools bitcoind elementsd clightning lnd ];
+        elementsd = pkgs1.elementsd;
+        mermaid = pkgs1.nodePackages.mermaid-cli;
+        lnd = pkgs1.lnd;
+        lwk = pkgs2.lwk;
+        electrs = blockstream-electrs;
 
-}
+    };
+    testpkgs = [ pkgs1.go pkgs1.bitcoind pkgs1.elementsd pkgs1.lnd pkgs2.lwk blockstream-electrs];
+    devpkgs = [ pkgs1.go_1_22 pkgs1.gotools pkgs1.bitcoind pkgs1.elementsd pkgs1.clightning pkgs1.lnd pkgs2.lwk blockstream-electrs];
+}