SUMMARY when we try to attach to a SIGSTOP'ed process, then GDB attaching fails STEPS TO REPRODUCE 1. start app 2. ctrl+z to stop 3. attach heaptrack OBSERVED RESULT heaptrack output will be written to "/home/milian/projects/build/heaptrack/heaptrack.threaded.88898.zst" injecting heaptrack into application via GDB, this might take some time... The program received a signal in another thread while making a function call from GDB. Evaluation of the expression containing the function (malloc) will be abandoned. When the function is done executing, GDB will silently stop. No symbol "heaptrack_inject" in current context. injection finished EXPECTED RESULT it works