hi folks, tl;dr: can we stop building/testing master on bionic for a better GCC? long story: two months ago, we migrated[0] our CI jobs running "make check" from ubuntu/bionic to ubuntu/focal so we have access to more packages offered by focal for testing. but we are still suffering[1] from the ancient packages offered by bionic: - buggy tcmalloc. see https://github.com/ceph/ceph/pull/41340 - GCC 7.5.0 shipped along with ubuntu/bionic. i think the support of std::filesystem is just the tip of the iceberg, as we've migrated to C++17, there will be more and more demand for a compiler and a standard library with better C++17 (and C++20 in future) support. GCC-7 has good support[2] of C++17, but that does not imply that libstdc++ shipped along with GCC-7 has. but we have to build and test on bionic[3], for couple reasons: - some upgrade tests from octopus are performed on bionic. for instance, see https://github.com/ceph/ceph/tree/master/qa/suites/upgrade/pacific-x/parall… - cosbench used by perf tests needs bionic: see https://tracker.ceph.com/issues/49139 - // please note rados/thrash-old-clients/distro$/ubuntu_18.04.yaml is safe even after we stop building master on bionic, as we've switched[4] to cephadm for thrash-old-clients and because of https://tracker.ceph.com/issues/50218, we cannot use ubuntu-toolchain-r PPA repo for newer GCC. so, i propose we - drop building/testing master on bionic. - drop the upgrade test from pacific on bionic - drop the cosbench workload from rados/perf test suites what do you think? -- [0] https://tracker.ceph.com/issues/49653 [1] https://github.com/ceph/ceph/pull/41433#discussion_r636604231 [2] https://gcc.gnu.org/projects/cxx-status.html [3] https://github.com/ceph/ceph-build/pull/1794#issuecomment-815435506 [4] https://github.com/ceph/ceph/pull/32377