我在 ubuntu 18.04 和 ubuntu 20.04 中找不到任何核心转储文件，即使我已经更改了core file size并且/proc/sys/kernel/core_pattern：
smart@stable:~$ ulimit -c unlimited
smart@stable:~$ ulimit -a
core file size (blocks, -c) unlimited
data seg size (kbytes, -d) unlimited
scheduling priority (-e) 0
file size (blocks, -f) unlimited
pending signals (-i) 63699
max locked memory (kbytes, -l) 65536
max memory size (kbytes, -m) unlimited
open files (-n) 1048576
pipe size (512 bytes, -p) 8
POSIX message queues (bytes, -q) 819200
real-time priority (-r) 0
stack size (kbytes, …