Hi Yujie,
> > >
> > > > > arch/um/drivers/harddog_user.c:6:10: fatal error: stdio.h: No such file or
> > > > > directory
> > > 6 | #include <stdio.h>
> > > | ^~~~~~~~~
> > > compilation terminated.
> >
> > Wild guess, is this a nolibc toolchain?
>
> The bot is using the gcc-11 provided by debian distribution, so we think
> it is not a "nolibc toolchain".
>
> compiler: gcc-11 (Debian 11.3.0-8) 11.3.0
>
> We can reproduce it on commit fc54a4f15988, and its parent commit is
> clean. Please help give some guidance if anything wrong in our test
> flow. Thanks.
>
That was just a misinterpretation. The real issue was fixed by commit
73a23d771033 ("um: harddog: fix modular build").
johannes
