[boost] [rational] release (optimized) builds are failing unit tests

Subject: [boost] [rational] release (optimized) builds are failing unit tests
From: James E. King, III (jking_at_[hidden])
Date: 2018-06-12 19:26:36

I am adding CI to Boost.Rational and the unit tests are failing for
different levels of optimization on different compilers.  Before I dig into
it further, does anybody have any idea what this might be?

https://github.com/boostorg/rational/issues/18

See issue for error output.

Ubuntu Bionic

gcc
unit test succeeds: -O0, -O1
unit test fails: -O2, -O3
boost_at_17b66a9efac4:/boost/libs/rational/test$ g++ --version
g++ (Ubuntu 7.3.0-16ubuntu3) 7.3.0clang

unit test succeeds: -O0
unit test fails: -O1, -O2, -O3
boost_at_17b66a9efac4:/boost/libs/rational/test$ clang++-6.0 --version
clang version 6.0.0-1ubuntu2 (tags/RELEASE_600/final)
Target: x86_64-pc-linux-gnu
Thread model: posix
InstalledDir: /usr/bin

To reproduce, try:

boost_at_17b66a9efac4:/boost/libs/rational/test$ ../../../b2 toolset=clang
variant=release rational_test

I am using the ubuntu bionic docker container to do the build in. See
boostorg/boost#184 <https://github.com/boostorg/boost/pull/184>