solve linking issue on non macOS systems

CMakeLists.txt

@@ -4,6 +4,7 @@ set(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} "${CMAKE_SOURCE_DIR}/cmake/modules/")
 project(pygin)
 
 set(CMAKE_CXX_STANDARD 14)
+set(CMAKE_POSITION_INDEPENDENT_CODE ON)
 
 # find ginac on system and add headers to include path
 find_package(GiNaC REQUIRED)