switch to libprotobuf

[djsutherland]

No description provided.

[conda-forge-linter]

Hi! This is the friendly automated conda-forge-linting service.

I just wanted to let you know that I linted all conda-recipes in your PR (recipe) and found it was in an excellent condition.

[djsutherland]

Hmm:

[100%] Linking CXX executable minimal
../../src/shogun/libshogun.so.18.0: undefined reference to `google::protobuf::Message::InitializationErrorString() const'
../../src/shogun/libshogun.so.18.0: undefined reference to `google::protobuf::Message::GetTypeName() const'
../../src/shogun/libshogun.so.18.0: undefined reference to `google::protobuf::internal::AssignDescriptors(std::string const&, google::protobuf::internal::MigrationSchema const*, google::protobuf::Message const* const*, unsigned int const*, google::protobuf::MessageFactory*, google::protobuf::Metadata*, google::protobuf::EnumDescriptor const**, google::protobuf::ServiceDescriptor const**)'
../../src/shogun/libshogun.so.18.0: undefined reference to `google::protobuf::MessageFactory::InternalRegisterGeneratedFile(char const*, void (*)(std::string const&))'
collect2: error: ld returned 1 exit status

Also, it was actually pulled in from defaults, because we only have 3.5 in conda-forge even though conda-forge-pinning has it at 3.4....

[djsutherland]

Not worth debugging until conda-forge switches to libprotobuf 3.5 (conda-forge/conda-forge-pinning-feedstock#14), since all this gains over the current build is (hopefully) protobuf support on Windows.

[jakirkham]

So the protobuf on conda-forge had both C++ and Python included since PR ( conda-forge/protobuf-feedstock#4 ). The addition of libprotobuf merely broke out the C++ part.

[djsutherland]

At least at some point, I think it only had the C API and not the C++ API on Windows (because the Python C++ interaction was broken or something). Not finding where that was happening in a quick search and doesn't really matter, though. :)

[djsutherland]

Depends on conda-forge/libprotobuf-feedstock#2.

[djsutherland]

Was already done in #20, but making Windows protobuf support #22.