$ sudo pacman -S riscv64-linux-gnu-binutils riscv64-linux-gnu-gcc riscv64-linux-gnu-gdb qemu-arch-extra
$ git clone git@github.com:Ran1s/xv6-labs-2021.git
$ cd MIT-6.S081/
$ git checkout util
branch 'util' set up to track 'origin/util'.
Switched to a new branch 'util'
$ make qemu
出现错误：error: infinite recursion detected [-Werror=infinite-recursion]
在xv6-labs-2021/user/sh.c文件中, runcmd函数上面添加设置特殊属性的宏:
__attribute__((noreturn))
void
runcmd(struct cmd *cmd)
{
