CXX/LD -o .build_release/tools/upgrade_solver_proto_text.bin
.build_release/tools/upgrade_solver_proto_text.o: In function `main':
upgrade_solver_proto_text.cpp:(.text.startup+0x19b): undefined reference to `caffe::SolverNeedsTypeUpgrade(caffe::SolverParameter const&)'
upgrade_solver_proto_text.cpp:(.text.startup+0x1aa): undefined reference to `caffe::UpgradeSolverAsNeeded(std::string const&, caffe::SolverParameter*)'
collect2: error: ld returned 1 exit status
make: *** [.build_release/tools/upgrade_solver_proto_text.bin] Error 1
Not sure what is causing this error. I have successfully built caffe versions in the past.