For a flexible error trace mechanism, embodiments may be implemented for C/C++ interface libraries, or in programs written in C/C++ or other programming languages. In one embodiment, when an error occurs in a function call, a trace element may be recorded that may include the source file name, function name, line number and other information that may be used to identify the error. In one embodiment, the library function may call a plurality of library functions in a function call stack. For each of the plurality of library functions, if the library function generates an error, an error trace element may be added to the error trace. After completion of the library function, the program may obtain the error trace for the library function. The error(s), if any, may be debugged using the information in the obtained error trace.