Many callers of invoke fail to check for a return value. Of those that do check the value, most throw an exception or uassert if the return value != 0. Once we throw from invoke(), the following call sites need to be verified and updated accordingly:

mr.cpp:
State::~State()
State::init()
State::bailFromJs()
State::finalReduce()
State::checkSize()
jstests.cpp
benchrun.cpp