anchor.diff:      date -d "@$mtime" --utc >&2
     '' + ''
       echo "Building Archive ${name}" >&2
  -    tar --sort=name --owner=0 --group=0 --numeric-owner \
  +    ${tar}/bin/tar --sort=name --owner=0 --group=0 --numeric-owner \
         --no-acls --no-selinux --no-xattrs \
         --mode=go=rX,u+rw,a-s \
         --clamp-mtime --mtime=@$mtime \
  -      -c "${name'}" | brotli --quality 6 --output "$out"
  +      -c "${name'}" | ${brotli}/bin/brotli --quality 6 --output "$out"
       du -bhs "$out"
       cp "$out" "$TMPDIR/${name}"
     '';
  
positive.code: { lib
  , fetchurl
  , unzip
  }:
  
  { # Optionally move the contents of the unpacked tree up one level.
  
negative.code: , url ? null
  , urls ? []
  , extraPostFetch ? ""
  , version ? 1  # TODO: Remove the default value and provide a meaningful error
  , ... } @ args:
  
  let
  