Hi Fred, Étienne, On 2025-05-26 20:29, Étienne Mollier wrote: > PICCA Frederic-Emmanuel, on 2025-05-26: >> do you know what should de done in order to prepare the chroot in our case.
>> a sort of bind mount but when we tryed to bind mount something under /dev/, >> it enup with this error I'm not yet familiar with sbuild's unshare backend, but I assume that just like the autopkgtest-virt-unshare backend, it only supports bind mount of directories at most. So you could bind mount the necessary directory /dev/dri, but not the device /dev/kfd. I took a brief look at adding this a shorte while ago but shelved it for now as we are in hard freeze. For now, you'd have to use the podman backend to run tests. > I'm not sure yet how to expose devices the right way in unshare > mode. I would expect any method involving bind-mount to require > running the pre-build commands as root, and any method involving > mknod to require work with capabilities(7), user_namespaces(7) > and setcap(8), but implementation details are evading me so far. I think it should work just with user_namespaces, because rootless podman does it like that. This PoC seemed to work: christian@host$ unshare --user --map-root-user --mount root@host$ touch /tmp/kfd && mount --bind /dev/kfd /tmp/kfd && ls -l /tmp/kfd crw-rw---- 1 nobody nogroup 239, 0 Mai 26 22:56 /tmp/kfd Though I have to say, without some web searches pointing me to the solution of touching the file to bind-mount the device over, I would have not found this. (I strongly suspect that chown'ing won't be possible or won't fix the issue entirely. For podman, I had to jump through a few hoops, search for "setgroups" in [1]). Best, Christian [1]: https://salsa.debian.org/rocm-team/community/team-project/-/blob/master/doc/rocm-autopkgtests-in-containers.md
