anchor.diff:      x86_64-linux = x86_64-linux-version;
     }.${system} or throwSystem;
   
  -  src = let
  -    base = "https://downloads.slack-edge.com";
  -  in {
  -    x86_64-darwin = fetchurl {
  -      url = "${base}/releases/macos/${version}/prod/x64/Slack-${version}-macOS.dmg";
  -      sha256 = x86_64-darwin-sha256;
  -    };
  -    x86_64-linux = fetchurl {
  -      url = "${base}/linux_releases/slack-desktop-${version}-amd64.deb";
  -      sha256 = x86_64-linux-sha256;
  -    };
  -  }.${system} or throwSystem;
  +  src =
  +    let
  +      base = "https://downloads.slack-edge.com";
  +    in
  +      {
  +        x86_64-darwin = fetchurl {
  +          url = "${base}/releases/macos/${version}/prod/x64/Slack-${version}-macOS.dmg";
  +          sha256 = x86_64-darwin-sha256;
  +        };
  +        x86_64-linux = fetchurl {
  +          url = "${base}/linux_releases/slack-desktop-${version}-amd64.deb";
  +          sha256 = x86_64-linux-sha256;
  +        };
  +      }.${system} or throwSystem;
   
     meta = with lib; {
       description = "Desktop client for Slack";
  
positive.code:       /usr/bin/defaults write com.tinyspeck.slackmacgap SlackNoAutoUpdates -bool YES
      '';
    };
  in if stdenv.isDarwin
    then darwin
    else linux
  
negative.code: { lib
  , stdenv
  , fetchurl
  , dpkg
  , undmg
  