rr doesn't need or use checkpoint/restore functionality. it's insufficient because rr already needs to catch and emulate all syscalls made by a process, and unn

rr doesn't need or use checkpoint/restore functionality. it's insufficient because rr already needs to catch and emulate all syscalls made by a process, and unnecessary because once you're doing that it's (relatively) easy to also emulate getpid. it also requires CAP_SYS_ADMIN or CAP_CHECKPOINT_RESTORE.