Symbol lookup error at runtime even though nm reports symbol present

问题

I build my program like this:

g++ -std=c++11 myprog.cpp -o myprog -lqpid-proton-cpp

Then I run ./myprog and get this error:

symbol lookup error: ./myprog: undefined symbol: _ZN6proton10event_loop6injectESt8functionIFvvEE

Yet, nm reports the symbol is present in the library . . .

nm -D /usr/lib/libqpid-proton-cpp.so | grep _ZN6proton10event_loop6injectESt8functionIFvvEE

. . . yields:

000000000002f460 T _ZN6proton10event_loop6injectESt8functionIFvvEE

What am I missing here?

回答1:

Did you verify, e.g., using ldd myprog, that you looked at the correct shared object? There is a chance a different shared object is found.

来源：https://stackoverflow.com/questions/44273095/symbol-lookup-error-at-runtime-even-though-nm-reports-symbol-present