On Nov 8, 2019, at 20:03, Joshua Root wrote: > On 2019-11-9 10:28 , Jack Howarth wrote: >> I just noticed a really bizarre aspect to this Xcode 11 bug. If you >> build gmp manually from source with the default compiler flags in use... >> >> ./configure >> make >> make check >> >> the t-powm test case fails. However if you add -fstack-check >> explicitly on CFLAGS and CXXFLAGS, the t-powm test case failure is >> suppressed. >> >> ./configure CFLAGS='-O2 -fcheck-stack' CXXFLAGS='-O2 -fcheck-stack' >> make >> make check > > Are the default compiler flags '-O2'?
MacPorts default optimization flag is -Os.
