https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95137
--- Comment #16 from Rafael Avila de Espindola <rafael at espindo dot la> --- > @Rafael: Can you please append output with: > export UBSAN_OPTIONS="print_stacktrace=1" I also added halt_on_error=1:abort_on_error=1: It is ../tests/unit/coroutines_test.cc:11:5: runtime error: member call on misaligned address 0x000041b58ab3 for type 'struct awaiter', which requires 8 byte alignment 0x000041b58ab3: note: pointer points here <memory cannot be printed> Reactor stalled for 261 ms on shard 0. Backtrace: /lib64/libasan.so.6+0x0000000000045bad ... #0 0xf3605a in main::{lambda()#1}::operator()() const [clone .actor] ../tests/unit/coroutines_test.cc:11 #1 0xf3b20b in std::__n4861::coroutine_handle<void>::resume() const /usr/include/c++/10/coroutine:126 #2 0xf3b5ed in seastar::internal::coroutine_traits_base<>::promise_type::run_and_dispose() ../include/seastar/core/coroutine.hh:104 #3 0x11c8892 in seastar::reactor::run_tasks(seastar::reactor::task_queue&) ../src/core/reactor.cc:2151 #4 0x11cc8db in seastar::reactor::run_some_tasks() ../src/core/reactor.cc:2566 #5 0x11d1aa0 in seastar::reactor::run() ../src/core/reactor.cc:2721 #6 0xf4ef5e in seastar::app_template::run_deprecated(int, char**, std::function<void ()>&&) ../src/core/app-template.cc:202 #7 0xf4cf00 in seastar::app_template::run(int, char**, std::function<seastar::future<int> ()>&&) ../src/core/app-template.cc:115 #8 0xf4d3fa in seastar::app_template::run(int, char**, std::function<seastar::future<> ()>&&) ../src/core/app-template.cc:130 #9 0xf36a70 in main ../tests/unit/coroutines_test.cc:8 #10 0x7fac0533d041 in __libc_start_main (/lib64/libc.so.6+0x27041) #11 0xf3466d in _start (/home/espindola/scylla/scylla/seastar/build-dbg/tests/unit/coroutines_test+0xf3466d) I will try to reduce the test to not need seastar.