This lldb command should do the trick:
target stop-hook add --one-liner "frame variable"
Example:
(lldb) b print_all_variables Breakpoint 2: where = stophook`print_all_variables + 10 at main.c:14, address = 0x0000000100000eca (lldb) target stop-hook add --one-liner "frame variable" Stop hook #1 added. (lldb) c Process 4838 resuming (int) a = 10 (int) b = 20 (int) x = 32767 (int) i = 1606416664 (lldb) n (int) a = 10 (int) b = 20 (int) x = 10 (int) i = 1606416664 (lldb) n (int) a = 10 (int) b = 20 (int) x = 10 (int) i = 0 (lldb)