'Relative' in the sense that they can only sensibly compared to
another time value obtained using the same function during the
same program invocation.
Currently, this is only relevant when using LevelDB, and a newer version
of libstdc++, which uses a different C++ ABI which clang does not yet support.
A symptom of the problem are unexpected linking failures, caused by undefined
symbols, while other symbols from the same library do not cause errors.
The solution is a workaround, that avoids using the offending symbols, at the
cost of reduced functionality. As this currently only affects the text of an
error message, the impact is minor.
