Add -fPIC to compiler options

Release/src/subdir.mk

@@ -35,7 +35,7 @@ CPP_DEPS += \
 src/%.o: ../src/%.cpp
 	@echo 'Building file: $<'
 	@echo 'Invoking: GCC C++ Compiler'
-	g++ -DMS_WIN64 -I"$(PYTHON_INCLUDE)" -I"$(NUMPY_INCLUDE)" -O3 -Wall -c -fmessage-length=0 -MMD -MP -MF"$(@:%.o=%.d)" -MT"$(@:%.o=%.d)" -o"$@" "$<"
+	g++ -DMS_WIN64 -I"$(PYTHON_INCLUDE)" -I"$(NUMPY_INCLUDE)" -O3 -Wall -c -fmessage-length=0 -fPIC -MMD -MP -MF"$(@:%.o=%.d)" -MT"$(@:%.o=%.d)" -o"$@" "$<"
 	@echo 'Finished building: $<'
 	@echo ' '