Protobuf compiler version 3.0.0 doesn't match library version 2.6.1 - Aspera Transfer SDK

I am attempting to compile the sample programs from this tar ball: https://api.ibm.com/explorer/catalog...k/doc/overview

Code: $ cmake ..
-- The C compiler identification is GNU 7.5.0
-- The CXX compiler identification is GNU 7.5.0
-- Check for working C compiler: /usr/bin/cc
-- Check for working C compiler: /usr/bin/cc -- works
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Detecting C compile features
-- Detecting C compile features - done
-- Check for working CXX compiler: /usr/bin/c++
-- Check for working CXX compiler: /usr/bin/c++ -- works
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Detecting CXX compile features
-- Detecting CXX compile features - done
CMake Warning at /usr/local/share/cmake-3.16/Modules/FindProtobuf.cmake:499 (message):
Protobuf compiler version 3.0.0 doesn't match library version 2.6.1
Call Stack (most recent call first):
CMakeLists.txt:11 (include)


-- Found Protobuf: /usr/local/lib/libprotobuf.so;-lpthread (found version "2.6.1")
CMake Warning at /usr/local/share/cmake-3.16/Modules/FindProtobuf.cmake:499 (message):
Protobuf compiler version 3.0.0 doesn't match library version 2.6.1
Call Stack (most recent call first):
CMakeLists.txt:12 (find_package)


-- Configuring done
-- Generating doneWhat does this error message mean? How am I supposed to upgrade libprotobuf.so found in /usr/local/lib?

Does this mean I am supposed to download and compile protobuf by source? Currently I installed it through apt-get.

I am on Ubuntu 18.04.

Code: ~$ which protoc
/usr/bin/protoc

~$ protoc --version
libprotoc 3.0.0