I'm having an issue with OpenImageIO I don't understand.

The build is failing with a ton of errors like these:

/usr/bin/ld: ../../lib/libOpenImageIO.so.2.2.10: undefined reference to `Field3D::v1_7::SparseFile::Reference<Imath_2_5::Vec3<double> >::openFile()'
/usr/bin/ld: ../../lib/libOpenImageIO.so.2.2.10: undefined reference to `Field3D::v1_7::FieldCache<Imath_2_5::Vec3<float> >::ms_creationMutex'
/usr/bin/ld: ../../lib/libOpenImageIO.so.2.2.10: undefined reference to `Field3D::v1_7::SparseFile::Reference<Imath_2_5::Vec3<float> >::openFile()'
/usr/bin/ld: ../../lib/libOpenImageIO.so.2.2.10: undefined reference to `Field3D::v1_7::Field<Imath_2_5::Vec3<double> >::Vec Field3D::v1_7::Field3DInputFile::readLayers<Imath_2_5::Vec3<double> >(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&) const'
/usr/bin/ld: ../../lib/libOpenImageIO.so.2.2.10: undefined reference to `Field3D::v1_7::SparseFile::Reference<Imath_2_5::Vec3<half> >::openFile()'
/usr/bin/ld: ../../lib/libOpenImageIO.so.2.2.10: undefined reference to `Field3D::v1_7::MatrixFieldMapping::setLocalToWorld(Imath_2_5::Matrix44<double> const&)'

But libOpenImageIO.so is being linked with Field3D so I assume it's some interaction with openexr (the Imath_2_5 stuff). But when I look at the build for Field3D and OpenImageIO they both are building against the new openexr... 

Is this even Boost related? It doesn't look like it, but it built previously with the new openexr and the same version of Field3D before the boost change AFAICT.

Thanks,
RIchard