anchor.diff:  in
   runCommandLocal "${name}.desktop" {}
     ''
  -    mkdir -p $out/share/applications
  -    cat > $out/share/applications/${name}.desktop <<EOF
  +    mkdir -p "$out/share/applications"
  +    cat > "$out/share/applications/${name}.desktop" <<EOF
       [Desktop Entry]
       Type=${type}
       Exec=${exec}
  
positive.code: { lib, runCommandLocal }:
  { name
  , type ? "Application"
  , exec
  
negative.code: , categories ? "Application;Other;"
  , startupNotify ? null
  , extraEntries ? null
  , fileValidation ? true # whether to validate resulting desktop file.
  }:
  
  let
  