Bug#1121366: Ships /etc/kernel/header_postinst.d instead of /etc/kernel/headers_postinst.d

[Andras Korn <korn-debbugs@elan.rulez.org>]

On Thu, Nov 27, 2025 at 12:23:39PM +0100, Ben Hutchings wrote:

Hi,

> On Thu, 2025-11-27 at 00:56 +0100, Andreas Beckmann wrote:
> > On 11/25/25 11:38, Andras Korn wrote:
> > > Package: dkms
> > > Version: 3.2.2-1
> > 
> > > dkms ships a /etc/kernel/header_postinst.d/dkms file, which I suppose is expected to run when the linux-headers postinst scripts call:
> > > 
> > > linux-run-hooks headers postinst $version -- "$@"
> > > 
> > > However, linux-run-hooks doesn't use /etc/kernel/header_postinst.d, only /etc/kernel/headers_postinst.d, so the shipped /etc/kernel/header_postinst.d/dkms is never run.
> > > 
> > > (I verified this by adding --verbose --debug to the run-parts invocation in linux-run-hooks.)
> > 
> > This is an uncommunicated (maybe even unintended) path change on the 
> > src:linux side. Older kernels had this in linux-headers-*.postinst:
> [...]
> 
> This was an unintended change when I reimplemented hook handling in
> linux-run-hooks (in linux-base).  I just didn't notice that the
> directory prefix was previously "header_" and not "headers_" (like the
> package names).
> 
> Since nothing appears to install a hook in the new directories
> (/{etc,usr/share}/kernel/headers_postinst.d) yet, I will change this
> back rather than trying to support both.

I also found no package other than dkms install anything there, and dkms's
script hasn't actually run all this time with apparently nobody noticing
(because the same script is shipped in install.d as well).

I think it would be better to keep the name of
/etc/kernel/headers_postinst.d consistent with the -headers in the package
names, rather than modify linux-run-hooks to use the previous,
inconsistently-named directory.

Rationale: principle of least surprise. You don't know how many custom
setups that created /etc/kernel/headers_postinst.d/ (because people found
out that's what linux-run-hooks used) you'd be breaking by changing it.
Probably not many (I know of a total of 3 :), but I don't think there is a
compelling reason to do it.

If the dkms script shipped in /etc/kernel/header_postinst.d is not needed,
the dkms package can just drop it.

Summary: making a change risks breaking existing systems that depend on the
existing behaviour without any obvious benefit; not changing linux-run-hooks
carries no such risk.

Just my 2 cents.

András

-- 
            A bug is a feature that didn't make it into the manual.