I think here should be change to 'root' user Or add user 'ubuntu' to 'sudo' group, right?
ubuntu@linux-lab:/labs/linux-lab$ make boot
Downloading board bsp ...
git submodule update --init --remote /labs/linux-lab/boards/mipsel/malta/bsp
fatal: could not create work tree dir 'boards/mipsel/malta/bsp'.: Permission denied
Clone of 'https://gitee.com/tinylab/qemu-mipsel-malta.git' into submodule path 'boards/mipsel/malta/bsp' failed
make: *** [bsp-source] Error 1
ubuntu@linux-lab:/labs/linux-lab$ whoami
ubuntu
ubuntu@linux-lab:/labs/linux-lab$