libmythmetadata not compiling with clang++ 7.0.2 exiv2 0.25

[JYA]

linkage failure:

Undefined symbols for architecture x86_64:
  "Exiv2::CommentValue::CommentValue(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&)", referenced from:
      PictureMetaData::DecodeComment(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >) in imagemetadata.o
  "Exiv2::ImageFactory::open(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&, bool)", referenced from:
      PictureMetaData::PictureMetaData(QString const&) in imagemetadata.o
  "Exiv2::ExifKey::ExifKey(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&)", referenced from:
      PictureMetaData::GetTag(QString const&, bool*) in imagemetadata.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
make: *** [libmythmetadata-0.28.0.28.0.dylib] Error 1

tested on mac 10.11.3

[JYA]

typically those linking error occurs when using libstdc++ vs libc++ or C++11 stuff with incompatible libs.

[JYA]

hmmm..

I see that Qt SDK is built against libc++ while default packages are built against libstdc++ ; this is never going to work :(