Re: [PATCH] kbuild: rpm-pkg: Fix generating debuginfo manually.

[Lukas Herbolt <lukas@herbolt.com>]

On 2026-02-12 17:26, Nathan Chancellor wrote:
> Hi Lukas,
> 
> Thanks for the patch!
> 
> On Thu, Feb 12, 2026 at 02:58:56PM +0100, Lukas Herbolt wrote:
>> The ${OBJCOPY} and ${READELF} are not expanded into path to readelf
>> and objcopy binary so just use the binary name with the %{_bindir}
>> makro.
>> 
>> Signed-off-by: Lukas Herbolt <lukas@herbolt.com>
>> ---
>>  scripts/package/kernel.spec | 4 ++--
>>  1 file changed, 2 insertions(+), 2 deletions(-)
>> 
>> diff --git a/scripts/package/kernel.spec b/scripts/package/kernel.spec
>> index 0f1c8de1bd95..d032f6aff91b 100644
>> --- a/scripts/package/kernel.spec
>> +++ b/scripts/package/kernel.spec
>> @@ -109,11 +109,11 @@ echo 
>> /usr/lib/debug/lib/modules/%{KERNELRELEASE}/vmlinux > 
>> %{buildroot}/debuginf
>>  while read -r mod; do
>>  	mod="${mod%.o}.ko"
>>  
>> 	dbg="%{buildroot}/usr/lib/debug/lib/modules/%{KERNELRELEASE}/kernel/${mod}"
>> -	buildid=$("${READELF}" -n "${mod}" | sed -n 's@^.*Build ID: 
>> \(..\)\(.*\)@\1/\2@p')
>> +	buildid=$(%{_bindir}/eu-readelf -n "${mod}" | sed -n 's@^.*Build ID: 
>> \(..\)\(.*\)@\1/\2@p')
> 
> When using the binrpm-pkg target within Kbuild, I do see these expanded
> to their Kbuild value:
> 
>   ++ .../toolchains/gcc/15.2.0/bin/x86_64-linux-readelf -n 
> net/ipv6/netfilter/nf_reject_ipv6.ko
>   ++ sed -n 's@^.*Build ID: \(..\)\(.*\)@\1/\2@p'
> 
> but I guess use of the spec file is not limited to being within Kbuild?
> How are you using it? I guess using the srcrpm-pkg and building it
> manually?

Yes exactly; make srcrpm-pkg and then mock --rebuild <src.rpm> (which 
actually
runs rpmbuild in chroot).
Looking into it I guess the variables should be expanded after the make
srcrpm-pkg, but if I check the spec file:

I can see:
buildid=$("${READELF}" ....

So the mkspec is not expanding the variable.

> 
> I would prefer to keep use of these variables so that the user's choice
> of toolchain is properly respected. The proper way to fix this is 
> likely
> using a fallback only when the variable is not defined. Does this work
> for your usecase?
> 
> diff --git a/scripts/package/kernel.spec b/scripts/package/kernel.spec
> index 0f1c8de1bd95..c23ff98f63ed 100644
> --- a/scripts/package/kernel.spec
> +++ b/scripts/package/kernel.spec
> @@ -109,11 +109,11 @@ echo 
> /usr/lib/debug/lib/modules/%{KERNELRELEASE}/vmlinux > 
> %{buildroot}/debuginf
>  while read -r mod; do
>  	mod="${mod%.o}.ko"
>  
> 	dbg="%{buildroot}/usr/lib/debug/lib/modules/%{KERNELRELEASE}/kernel/${mod}"
> -	buildid=$("${READELF}" -n "${mod}" | sed -n 's@^.*Build ID: 
> \(..\)\(.*\)@\1/\2@p')
> +	buildid=$("${READELF:-readelf}" -n "${mod}" | sed -n 's@^.*Build ID: 
> \(..\)\(.*\)@\1/\2@p')
>  	link="%{buildroot}/usr/lib/debug/.build-id/${buildid}.debug"
> 
>  	mkdir -p "${dbg%/*}" "${link%/*}"
> -	"${OBJCOPY}" --only-keep-debug "${mod}" "${dbg}"
> +	"${OBJCOPY:-objcopy}" --only-keep-debug "${mod}" "${dbg}"
>  	ln -sf --relative "${dbg}" "${link}"
> 
>  	echo "${dbg#%{buildroot}}" >> %{buildroot}/debuginfo.list

Yeah that works for me.
-- 
-lhe