On Sat, Nov 30, 2024 at 8:31 AM Caleb Connolly
<caleb.connolly@linaro.org> wrote:
>
> Hi Masahiro,
>
> On 9/17/24 16:16, Masahiro Yamada wrote:
> > Keep the consistent behavior when this Makefile is invoked from another
> > directory.
>
> This breaks building in a chroot for me. I usually compile the kernel on
> my host and then use some tooling to just run the "package" step of an
> Alpine kernel package definition. See
>
> https://wiki.postmarketos.org/wiki/Compiling_kernels_with_envkernel.sh#Packaging_kernels_built_without_envkernel
>
> Since this requires mounting the source directory into a chroot, and
> then symlinking the output directory to the package "src" dir. It relies
> on the fact that make can be run from the output directory and
> implicitly relies on the include being relative since the absolute paths
> don't map inside the chroot.
I do not understand what is happening in your workflow, but presumably
you need to come up with a solution on your end (or in the pmos community).
- Kbuild never promised that $(srctree) is always a relative path.
$(srctree) is relative only when building in-tree (srctree=.)
or when the output directory is a sub-directory of the source tree.
(srctree=..) For other cases, $(srctree) is an absolute path.
Therefore, "include directive with an absolute path" is not something new.
- The wrapper Makefile generated in the output directory
is a bonus convenience for humans. It is not even required
to build the kernel from scripts.
Your report seems like a jungle of a chroot and mounts with a symlink.
I guess it just happened to work, relying on something Kbuild did not support.
>
> I'm not sure if breakages like this justify a revert, but I noticed this
> issue in -next the other day and thought it was at least worth reporting.
Thanks for the report, but I do not think this is worth a revert
for the above reasons.
> I wouldn't be surprised if other folks with other build systems get
> bitten by this too.
>
> Kind regards,
> Caleb
> >
> > Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
> > ---
> >
> > Makefile | 5 +++--
> > 1 file changed, 3 insertions(+), 2 deletions(-)
> >
> > diff --git a/Makefile b/Makefile
> > index ce646a6994a6..9f0ba07e8f25 100644
> > --- a/Makefile
> > +++ b/Makefile
> > @@ -643,8 +643,9 @@ ifdef building_out_of_srctree
> >
> > quiet_cmd_makefile = GEN Makefile
> > cmd_makefile = { \
> > - echo "\# Automatically generated by $(srctree)/Makefile: don't edit"; \
> > - echo "include $(srctree)/Makefile"; \
> > + echo "\# Automatically generated by $(abs_srctree)/Makefile: don't edit"; \
> > + echo "export KBUILD_OUTPUT = $(CURDIR)"; \
> > + echo "include $(abs_srctree)/Makefile"; \
> > } > Makefile
> >
> > outputmakefile:
>
--
Best Regards
Masahiro Yamada