fetchsvnssh: support `hash` attribute

{stdenvNoCC, subversion, sshSupport ? true, openssh ? null, expect}:

{username, password, url, rev ? "HEAD", sha256 ? ""}:

{lib, stdenvNoCC, subversion, sshSupport ? true, openssh ? null, expect}:

{username, password

, url, rev ? "HEAD"

, outputHash ? lib.fakeHash, outputHashAlgo ? null}:

lib.fetchers.withNormalizedHash { } (

  stdenvNoCC.mkDerivation {

    name = "svn-export-ssh";

    builder = ./builder.sh;

    nativeBuildInputs = [subversion expect];

  outputHashAlgo = "sha256";

    inherit outputHash outputHashAlgo;

    outputHashMode = "recursive";

  outputHash = sha256;

    sshSubversion = ./sshsubversion.exp;

    inherit username password url rev sshSupport openssh;

  }

)