Protocol Buffer Error on compile during GOOGLE_PRO

Question

I'm currently getting an error which points me to these lines in the header file produced by protoc:

#if 2006001 < GOOGLE_PROTOBUF_MIN_PROTOC_VERSION
#error This file was generated by an older version of protoc which is
#error incompatible with your Protocol Buffer headers.  Please
#error regenerate this file with a newer version of protoc.
#endif

But my protoc version matches the one above:

protoc --version
libprotoc 2.6.1

What am I doing wrong?

Originally my protoc version was 3.0.0 then reinstalled it by syncing back to 2.6.1 and doing the steps; make distclean, ./configure , make, make install to install the desired 2.6.1 version. I needed the older version since that's the one installed in our servers.

Answer 1

The problem is that the installed headers on your system (in /usr/include/google/protobuf or /usr/local/include/google/protobuf) are from a newer version of Protocol Buffers than your protoc. It may be the case that you have both versions installed in different locations, and the wrong one is being used.

But my protoc version matches the one above:

Yes, because that code was generated by your protoc, and it knows its own version. The code is asking: "Is my version (2006001) less than the minimum version which the installed headers claim is required (GOOGLE_PROTOBUF_MIN_PROTOC_VERSION)?"