checkmake: fix version information and date of the man page, refactor

pkgs/development/tools/checkmake/default.nix

@@ -1,4 +1,10 @@
-{ buildGoModule, fetchFromGitHub, pandoc, lib }:
+{ lib
+, buildGoModule
+, fetchFromGitHub
+, installShellFiles
+, pandoc
+, go
+}:
 
 buildGoModule rec {
   pname = "checkmake";
@@ -8,37 +14,42 @@ buildGoModule rec {
     owner = "mrtazz";
     repo = pname;
     rev = version;
-    sha256 = "sha256-Ql8XSQA/w7wT9GbmYOM2vG15GVqj9LxOGIu8Wqp9Wao=";
+    hash = "sha256-Ql8XSQA/w7wT9GbmYOM2vG15GVqj9LxOGIu8Wqp9Wao=";
   };
 
-  vendorSha256 = null;
+  vendorHash = null;
 
-  nativeBuildInputs = [ pandoc ];
+  nativeBuildInputs = [
+    installShellFiles
+    pandoc
+  ];
 
-  preBuild =
-    let
-      buildVars = {
-        version = version;
-        buildTime = "N/A";
-        builder = "nix";
-        goversion = "$(go version | egrep -o 'go[0-9]+[.][^ ]*')";
-      };
-      buildVarsFlags = lib.concatStringsSep " " (lib.mapAttrsToList (k: v: "-X main.${k}=${v}") buildVars);
-    in
-    ''
-      buildFlagsArray+=("-ldflags=${buildVarsFlags}")
-    '';
+  ldflags = [
+    "-s"
+    "-w"
+    "-X=main.version=${version}"
+    "-X=main.buildTime=1970-01-01T00:00:00Z"
+    "-X=main.builder=nixpkgs"
+    "-X=main.goversion=go${go.version}"
+  ];
 
-  ldflags = [ "-s" "-w" ];
+  postPatch = ''
+    substituteInPlace man/man1/checkmake.1.md \
+      --replace REPLACE_DATE 1970-01-01T00:00:00Z
+  '';
+
+  postBuild = ''
+    pandoc man/man1/checkmake.1.md -st man -o man/man1/checkmake.1
+  '';
 
   postInstall = ''
-    mkdir -p $out/share/man/man1
-    pandoc -s -t man -o $out/share/man/man1/checkmake.1 man/man1/checkmake.1.md
+    installManPage man/man1/checkmake.1
   '';
 
   meta = with lib; {
     description = "Experimental tool for linting and checking Makefiles";
     homepage = "https://github.com/mrtazz/checkmake";
+    changelog = "https://github.com/mrtazz/checkmake/releases/tag/${src.rev}";
     license = licenses.mit;
     maintainers = with maintainers; [ vidbina ];
     longDescription = ''