Got undefined reference to google protobuf when make all

[avan...@gmail.com]

When I make all in the caffe dir, I got the following error messages saying there are undefined reference to protobuf:

CXX/LD -o .build_release/tools/convert_imageset.bin
.build_release/lib/libcaffe.so: undefined reference to `google::protobuf::io::CodedOutputStream::WriteVarint64ToArray(unsigned long long, unsigned char*)'
.build_release/lib/libcaffe.so: undefined reference to `google::protobuf::internal::WireFormatLite::WriteInt64(int, long long, google::protobuf::io::CodedOutputStream*)'
.build_release/lib/libcaffe.so: undefined reference to `google::protobuf::UnknownFieldSet::AddVarint(int, unsigned long long)'
.build_release/lib/libcaffe.so: undefined reference to `google::protobuf::io::CodedOutputStream::VarintSize64(unsigned long long)'
.build_release/lib/libcaffe.so: undefined reference to `google::protobuf::io::CodedOutputStream::WriteVarint64(unsigned long long)'
collect2: error: ld returned 1 exit status
make: *** [.build_release/tools/convert_imageset.bin] Error 1

Anyone has any idea about how to fix this?

Thanks a lot!