anchor.diff:  
       src = fetchurl {
         url = "https://releases.mattermost.com/${version}/mattermost-${version}-linux-amd64.tar.gz";
  -      sha256 = "1p1qxzrd6rj1i43vj18ysknrw2v02s7llx94nrdd5lk10ayzmg63";
  +      sha256 = "kRerl3fYRTrotj86AIFSor3GpjhABkCmego1ms9HmkQ=";
       };
   
       installPhase = ''
  
positive.code: { lib, stdenv, fetchurl, fetchFromGitHub, buildGoPackage, buildEnv }:
  
  let
    version = "5.25.3";
  
    mattermost-server = buildGoPackage rec {
      pname = "mattermost-server";
  
negative.code:       owner = "mattermost";
        repo = "mattermost-server";
        rev = "v${version}";
        sha256 = "BssrTfkIxUbXYXIfz9i+5b4rEYSzBim+/riK78m8Bxo=";
      };
  
      goPackagePath = "github.com/mattermost/mattermost-server";
  