GDB breakpoint like python's breakpoint
Launch ugdb and attach to current process with new tmux window.

use breakpoint;
Require nightly.
set ptrace_scope
echo 0 | sudo tee /proc/sys/kernel/yama/ptrace_scope
Make gdb to attach to the program.
Recommendation
Multithreadding rust programs can call SIGSTOP many times. I recommend you to add following command into your .gdbinit file. So I used SIGINT instead of SIGSTOP on the second and later breakpoint calls.
handle SIGSTOP "nostop" "pass" "noprint"