https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63332
--- Comment #7 from Jonathan Wakely <redi at gcc dot gnu.org> --- Aha, so that's the culprit. I really think we should be outputting in an exact format, not via conversion to/from decimal. > BTW, I did this manually as I'm not very proficient with `runtest`, isn't > there a shortcut to somehow run only this test? Yep, in the $target/libstdc++-v3 build dir: make check RUNTESTFLAGS=conformance.exp=ext/random/k_distribution/operators/serialize.cc You can also use shell wildcards e.g. RUNTESTFLAGS=conformance.exp=ext/*
