Arch Linux

Description: DKMS fails to clean the build area after a kernel is updated unless the user manually removes DKMS. The result is building modules that cannot be used with the newer kernel.

Example error when trying to use a module under these conditions: ERROR: could not insert 'vboxdrv': Exec format error

Additional info:
* package version(s) 2.2.0.3-11

Steps to reproduce:
1) Install a custom kernel and initialize dkms to build some modules. I used virtualbox-source for example.
1a) sudo dkms install vboxhost/4.1.18
2) Update the custom kernel to a newer version and reboot into it. Uninstall the old modules and rebuild them with dkms. You will find that they do not work.
2a) sudo dkms uninstall vboxhost/4.1.18
2b) sudo dkms install vboxhost/4.1.18

--- See output attached called "stale_rebuild"

3) Uninstall dkms and reinstall it. Repeat step 2b

-- See output attached called "fresh_rebuild"

Note the difference is that after a fresh install of dkms, it cleans the build area when it is freshly installed. Here is the diff of those two files:

$ diff fresh_rebuild stale_rebuild
3,12d2
< Kernel preparation unnecessary for this kernel. Skipping...
<
< Building module:
< cleaning build area....
< make KERNELRELEASE=3.5.2-1-ck -C /usr/lib/modules/3.5.2-1-ck/build M=/var/lib/dkms/vboxhost/4.1.18/build........
< cleaning build area....
<
< DKMS: build completed.
<
< vboxdrv.ko: