fetchFromGitHub: drop unzip

  useFetchGit = fetchSubmodules || (leaveDotGit == true) || deepClone || forceFetchGit || (sparseCheckout != []);

  # We prefer fetchzip in cases we don't need submodules as the hash

  # is more stable in that case.

  fetcher = if useFetchGit then fetchgit else fetchzip;

  fetcher = if useFetchGit then fetchgit else fetchzip.override { withUnzip = false; };

  privateAttrs = lib.optionalAttrs private {

    netrcPhase = ''

      if [ -z "''$${varBase}USERNAME" -o -z "''$${varBase}PASSWORD" ]; then