> Don't name it with Japanese characters,
It is default.
> If that doesn't work, the error might mean that you have to run "make &&
make install" as "sudo make && make install".
It is in the log.
> Lastly, you are using an older kernel that's from early 2018. If I was
running a modern digital tablet, I'd be seriously thinking about using a
kernel that's not over 2 years old. Lots of new kernels available at jxself's
web page: https://jxself.org/linux-libre/
Indeed, I have just checked the kernel and it was the old kernel. Strange. I
was under the impression that I was using the stable LTS linux-libre kernel.
I have no idea why I am using the default kernel.
So by the default, Trisquel 9 does not support modern (I don't think my table
is modern though) digital tablets?