guix/corepkgs/fetchurl/fetchurl.fix

Function(["url", "md5"],
  Package(
    [ ("build", Relative("fetchurl/fetchurl.sh"))
    , ("url", Var("url"))
    , ("md5", Var("md5"))
    , ("name", BaseName(Var("url")))
    , ("id", Var("md5"))
    ]
  )
)