[Bug libstdc++/85845] [9 Regression] Many libstdc++ test failures

[Paolo Carlini]

Hi,

On 22/05/2018 11:24, Richard Biener wrote:
> On Mon, May 21, 2018 at 7:01 PM François Dumont <frs.dumont@gmail.com>
> wrote:
>
>> I just committed this patch as trivial.
>> I must have run tests without rebuilding pre-compiled headers. I'll have
>> to find out how to build tests without pre-compiled headers to avoid it
>> in the future.
> I configure with --disable-libstdcxx-pch which also reduces build-time.
If I understand correctly the issue, to test without PCHs I used to 
configure / test / etc normally and then by-hand remove the generated 
PCHs and run make check inside libstdc++-v3/testsuite (*not* inside 
libstdc++-v3) in case of need. It's an HACK, which exploits sort of a 
bug: in that case make check doesn't lead to the automatic regeneration 
of the PCHs.

Paolo.