The downloads.haskell.org server is misconfigured. It's always gzipping its response content, ignoring the Accept-Encoding headers. Even if you set Accept-Encoding: identity the server sends a compressed response. This prevents automated version update checking. For details, see: https://lists.macports.org/pipermail/macports-dev/2019-December/041581.html https://lists.macports.org/pipermail/macports-dev/2019-December/041581.html