Thank you for the bug report. You are right. I entirely missed to update the readme file. Will do it in the next update
s3nt fr0m a $martph0ne, excuse typ0s On Sat, 5 Sept, 2026, 02:25 John Scott, <[email protected]> wrote: > Control: found -1 7.1um1 > > (By the way, why don't we make the version number for the user-mode-linux > binary package reflect the version of linux-source-* package that was used > at build-time, so that rebuilds of user-mode-linux against newer > linux-source-* packages will be identified as upgrades? The version numbers > of binary packages need not have any relation to their source packages. The > status quo is also troublesome for bug reports like this, because '7.1um1' > isn't a useful identifier for the kernel used. If there's not a particular > reason for this I can try a merge request.) > > I ran into this issue in a quite different context, having built > user-mode-linux against 7.1.8-1~bpo13+1 on Trixie and wanting to give it a > try to investigate a kernel issue. A succinct statement and a patch were > proposed in 2024 at > https://lore.kernel.org/all/[email protected]/ > but it doesn't seem like anything happened to it and it was just forgotten. > Here's a clear manifestation: /usr/share/doc/user-mode-linux/README.Debian > includes the conventional advice of > > Kernel modules > > -------------- > > Modules are installed in /usr/lib/uml/modules/<version>. The easiest > way to get to them from within UML is to use hostfs, e.g.: > > mount -t hostfs -o /usr/lib/uml/modules hostfs /lib/modules > > or: > > echo "hostfs /lib/modules hostfs /usr/lib/uml/modules 0 0" >> > /etc/fstab > > Note that the subdirectory of the host is specified as a "keyless" mount > option, and the source device name (the word "hostfs" here) is not used but > ignored. This doesn't actually work anymore though: > > ~# mount -t hostfs -o /usr/lib/uml/modules hostfs /lib/modules > > mount: /usr/lib/modules: fsconfig() failed: hostfs: Unknown parameter > '/usr/lib/uml/modules'. > > dmesg(1) may have more information after failed mount system call. > > It's buried very deep in the mailing list thread at > https://lore.kernel.org/linux-um/[email protected]/ > but I found that using a key name of "hostfs" makes everything work: > > ~# mount -t hostfs -o hostfs=/usr/lib/uml/modules hostfs /lib/modules > > ~# ls /lib/modules > > 7.1.8 > (correct!) > > So if this apparent regression is not going to be fixed in the kernel, > being a couple years old at this point, we need to update documentation to > use the "hostfs=" key. We ought to do this in README.Debian, but also no > other documentation about UML (Rob Landley's site, kernel.org UML HowTo > v2, ...) has addressed this yet. This is why it's been so hard for me to > find. >
