At Mon, 5 Apr 2021 07:04:09 +0000, "tsunakawa.takay@fujitsu.com" <tsunakawa.takay@fujitsu.com> wrote in
> From: osumi.takamichi@fujitsu.com <osumi.takamichi@fujitsu.com>
> > By the way, when I build postgres with this patch and enable-coverage option,
> > the results of RT becomes unstable. Does someone know the reason ?
> > When it fails, I get stderr like below
> >
> > t/001_start_stop.pl .. 10/24
> > # Failed test 'pg_ctl start: no stderr'
> > # at t/001_start_stop.pl line 48.
> > # got:
> > 'profiling:/home/k5user/new_disk/recheck/PostgreSQL-Source-Dev/src/bac
> > kend/executor/execMain.gcda:Merge mismatch for function 15
> > # '
> > # expected: ''
> > t/001_start_stop.pl .. 24/24 # Looks like you failed 1 test of 24.
> > t/001_start_stop.pl .. Dubious, test returned 1 (wstat 256, 0x100) Failed 1/24
> > subtests
> >
> > Similar phenomena was observed in [1] and its solution seems to upgrade my
> > gcc higher than 7. And, I did so but still get this unstable error with
> > enable-coverage. This didn't happen when I remove enable-option and the
> > make check-world passes.
>
> Can you share the steps you took? e.g.,
>
> $ configure --enable-coverage ...
> $ make world
> $ make check-world
> $ patch -p1 < your_patch
> $ make world
> $ make check-world
>
> A bit of Googling shows that the same error message has shown up in the tests of other software than Postgres. It
doesn'tseem like this failure is due to your patch.
I didn't see that, but found the following article.
https://stackoverflow.com/questions/2590794/gcov-warning-merge-mismatch-for-summaries
> This happens when one of the objects you're linking into an executable
> changes significantly. For example it gains or loses some lines of
> profilable code.
It seems like your working directory needs some cleanup.
regards.
--
Kyotaro Horiguchi
NTT Open Source Software Center
