libpmemobj-cpp upgrade to 1.13.0-2 causes issues (on ppc64el only)

[Frank Heimes]

Canonical engineering recently started to upgrade the universe package “libpmemobj-cpp” to 1.13.0-2 (on impish) and ran into some issues while rebuilding.
And these seem to be ppc64el specific regressions.

Now asking the IBM Power team if this is known and if there are any ideas:

https://launchpad.net/ubuntu/+source/libpmemobj-cpp/1.13.0-2/

https://launchpad.net/ubuntu/+source/libpmemobj-cpp/1.13.0-2/+build/21966756

https://launchpadlibrarian.net/557792526/buildlog_ubuntu-impish-ppc64el.libpmemobj-cpp_1.13.0-2_BUILDING.txt.gz

“obj-powerpc64le-linux-gnu/tests/segment_vector_array_expsize_assign_exceptions_oom /<<PKGBUILDDIR>>/obj-powerpc64le-linux-gnu/test/segment_vector_array_expsize_assign_exceptions_oom_0_none/testfile failed: 139”

[James O'Connor (jpoc)]

Same/similar libpmemobj-cpp-1.13.0-2 source seems to have built ok for Debian sid ppc64el

https://buildd.debian.org/status/logs.php?pkg=libpmemobj-cpp

On impish it seems all the make check errors are oom related

The following tests FAILED:
 270 - segment_vector_array_expsize_assign_exceptions_oom_0_none (Failed)
 271 - segment_vector_array_expsize_assign_exceptions_oom_0_memcheck (Failed)
 282 - segment_vector_array_expsize_capacity_exceptions_oom_0_none (Failed)
 283 - segment_vector_array_expsize_capacity_exceptions_oom_0_memcheck (Failed)
 310 - segment_vector_array_expsize_modifiers_exceptions_oom_0_none (Failed)
 311 - segment_vector_array_expsize_modifiers_exceptions_oom_0_memcheck (Failed)
 332 - segment_vector_vector_expsize_assign_exceptions_oom_0_none (Failed)
 333 - segment_vector_vector_expsize_assign_exceptions_oom_0_memcheck (Failed)
 344 - segment_vector_vector_expsize_capacity_exceptions_oom_0_none (Failed)
 345 - segment_vector_vector_expsize_capacity_exceptions_oom_0_memcheck (Failed)
 372 - segment_vector_vector_expsize_modifiers_exceptions_oom_0_none (Failed)
 373 - segment_vector_vector_expsize_modifiers_exceptions_oom_0_memcheck (Failed)
 394 - segment_vector_vector_fixedsize_assign_exceptions_oom_0_none (Failed)
 395 - segment_vector_vector_fixedsize_assign_exceptions_oom_0_memcheck (Failed)

I'll keep digging for differences between the debian and ubuntu build environments.

[James O'Connor (jpoc)]

From frediz:

@jpoc seems like compiling with no optimization makes the tests pass. I know that one of the differences between Ubuntu and Debian is the level of optimization in the gcc default profile

Also using gcc-10 with optimization works.. so there's something with gcc-11 and optimization flags

[Frédéric Bonnard (frediz)]

Ok so since gcc-11, it won't pass tests with -O3, neither O2.
Got it work with O1.
```
export DEB_CXXFLAGS_MAINT_STRIP = -O3
export DEB_CXXFLAGS_MAINT_APPEND = -O1
```

As it worked fine as is with gcc-10 on Impish, I guess it's definitely
something for the toolchain team.

[Frank Heimes (fheimes)]

Thx Frédéric and thx James,
look like there are some more cases like this with gcc 11 and higher optimizations enabled:
https://bugs.launchpad.net/ubuntu/+source/mesa/+bug/1943818
https://bugs.launchpad.net/ubuntu/+source/ruby2.7/+bug/1943823
Would be indeed good if the toolchain team can have a look, since I think they are all similar.

[James O'Connor (jpoc)]

I am still working on isolating this bug and reporting with gcc upstream. To get further buy in from the IBM power toolchain team, I'm reproducing with the IBM Power Advance Toolchain 15.0-1 based on gcc-11.2.1-ee1df65e9233

https://www.ibm.com/support/pages/advtool-install

https://github.com/advancetoolchain/advance-toolchain/releases/tag/at15.0-1