yara: refactor

- add mainProgram
- remove marketing buzz from description

pkgs/tools/security/yara/default.nix

@@ -1,4 +1,5 @@
-{ lib, stdenv
+{ lib
+, stdenv
 , fetchFromGitHub
 , fetchpatch
 , autoreconfHook
@@ -20,8 +21,8 @@ stdenv.mkDerivation rec {
 
   src = fetchFromGitHub {
     owner = "VirusTotal";
-    repo = pname;
-    rev = "v${version}";
+    repo = "yara";
+    rev = "refs/tags/v${version}";
     hash = "sha256-AecHsUBtBleUkWuYMQ4Tx/PY8cs9j7JwqncBziJD0hA=";
   };
 
@@ -64,10 +65,12 @@ stdenv.mkDerivation rec {
   doCheck = enableStatic;
 
   meta = with lib; {
-    description = "The pattern matching swiss knife for malware researchers";
+    description = "Tool to perform pattern matching for malware-related tasks";
     homepage = "http://Virustotal.github.io/yara/";
+    changelog = "https://github.com/VirusTotal/yara/releases/tag/v${version}";
     license = licenses.asl20;
     maintainers = with maintainers; [ fab ];
+    mainProgram = "yara";
     platforms = platforms.all;
   };
 }