• Cédric Roux's avatar
    Revert "fix nettle" · 76574a1a
    Cédric Roux authored
    This reverts commit d31634c3.
    Laurent Thomas had a problem on one machine with the build_oai
    way of checking for nettle.
    The problem with the alternative solution of including nettle/bignum.h
    is that it is very unclear.
    The problem with nettle is that the file nettle/config.h does not
    exist for version 2. It was introduced in version 3.
    We want to support both versions, but there is an API incompatibility.
    So we need an #if #else mechanism.
    The file nettle/bignum.h is present in both versions 2 and 3 and it
    includes nettle/version.h in the version 3.
    So by including this file, we can check for the existence of
    NETTLE_VERSION_MAJOR (that comes from nettle/config.h) in the
    But as you can see, the reasoning is way too complex.
    So it's better to keep the check in cmake_targets/CMakeLists.txt.
    As long as we support version 2 this will be the way to go.
    It is possible to force a given version in specific non-generic
    customized environments.