Bug#948257: depmod: ERROR: ../libkmod/libkmod.c:515 lookup_builtin_file() could not open builtin file '/var/tmp/mkinitramfs_N1a1Mk/lib/modules/5.4.0-1-amd64/modules.builtin.bin'

[Michael Jeanson <mjeanson@debian.org>]

On 2020-01-06 7:46 p.m., Benjamin Poirier wrote:
> I'm not sure if it's related but I saw almost the same error on last
> upgrade (but for 5.4.0-2):
> 
> depmod: ERROR: ../libkmod/libkmod.c:515 lookup_builtin_file() could not open builtin file '/var/tmp/mkinitramfs_J2sneW/lib/modules/5.4.0-2-amd64/modules.builtin.bin'
> 
> and I now get:
> 
> root@vsid:~# lttng list --kernel
> Error: Unable to list kernel events: Kernel tracer not available
> root@vsid:~# journalctl -u lttng-sessiond.service
> [...]
> Jan 07 09:33:20 vsid lttng-sessiond[403]: Error: Failed to load kmod library resources
> Jan 07 09:33:20 vsid lttng-sessiond[403]: Warning: No kernel tracer available
> 
> lttng-modules-dkms is installed. I can load the modules manually but I
> still get the same error.
> 

Hi,

If you had just installed the lttng-modules-dkms and lttng-tools packages,
it's possible that the lttng-sessiond deamon was started before the kernel
modules were built and so it couldn't load them. Simply restarting the
sessiond should fix this.

Cheers,

Michael