sth wrong about my environment

[FlyingFatty]

I install almost everything recommended, buildroot, binwalk, gdb-multiarch, pwndbg, pwntools, qemu and maybe something more. And my commands are that:
`ubuntu@ubuntu:~/Desktop/DVRF/_DVRF_v03.bin.extracted/squashfs-root$ ./qemu-mipsel-static -L ./ -g 1234 ./pwnable/Intro/stack_bof_01
Usage: stack_bof_01
-By b1ack0wl

sudo chroot . ./qemu-mipsel-static -g 1234 ./pwnable/Intro/stack_bof_01

ubuntu@ubuntu:~/Desktop/DVRF/_DVRF_v03.bin.extracted/squashfs-root$ gdb-multiarch pwnable/Intro/stack_bof_01
(gdb) set architecture mips
(gdb) target remote 127.0.0.1:1234
(gdb) c
(gdb) disass main
`

The results are:
warning: remote target does not support file transfer, attempting to access files from local filesystem. Reading symbols from /home/ubuntu/Desktop/DVRF/_DVRF_v03.bin.extracted/squashfs-root/lib/ld-uClibc.so.0...(no debugging symbols found)...done. 0x7f7b9a80 in _start () from /home/ubuntu/Desktop/DVRF/_DVRF_v03.bin.extracted/squashfs-root/lib/ld-uClibc.so.0 (gdb) c Continuing. [Inferior 1 (Remote target) exited with code 01]
Actually there is an warning and exited, which means that gdb can not attach the "DVRF" process, and I do not know what to do more. Since the blog is no longer exist, could you please tell me sth about it? Thx very much!