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

[Nathan Chancellor <nathan@kernel.org>]

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?

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