On Sun, 12 Sept 2021 at 09:04, Masahiro Yamada <masahiroy@xxxxxxxxxx> wrote: > > On Sat, Sep 11, 2021 at 7:45 AM Markus Mayer <mmayer@xxxxxxxxxxxx> wrote: > > > > Here is what I have. > > > > $ cat Makefile > > > > export KERNEL_DIR = /local/users/mmayer/linux-5.4 > > > From this line, I understand how to reproduce the case. > > The key is 'linux-5.4' Sorry about that. I am glad to not be dealing with 4.9 that much anymore, so 5.4 is still "new-ish" to me. And 5.10 is the bleeding edge in my world. Goes to show that everything is relative. > In your initial email, you mentioned that this happened on > > * newish kernel (>=5.1) > > So, I used the latest kernel for testing, > but this does not happen after > bcf637f54f6d2515d4c9c81808faf01848916152 > because the M= parameter is parsed before the sub-make. > > By running your test code on linux 5.4, yes, > I can observe the same symptom. Thanks for trying out a 5.4 kernel. > The root case seams, GNU Make changes > the origin of variables to 'environment'. > I do not know if it is an intended behavior. > (maybe, better to ask the GNU Make maintainer) [...] > So, this is what your can tell: > > - The behavior of the -e option seems to have a weird > side-effect. > Later, I will ask this to the GNU Make maintainer > to see whether it is a bug or not. > > - I do not want to support the -e option. I do not think > it is a commonly-used option because you are the > first person who asked this since Linux 5.4. > (notice Linux 5.4 is almost two years old) > > - If you use the latest kernel > (after bcf637f54f6d251), you will be able to build > external modules with the -e option. > But, I recommend you to not use -e. > > - If you still insist on the -e option on Linux 5.4, > you can cherry-pick bcf637f54f6d251 > (but it is out of scope of the support of the community) > > Maybe, better to consider removing the -e option. I will forward the recommendation to see what can be done. Cherry picking the patch you are recommending should tide us over in the meantime. I will give it a shot. Thanks for your help. Regards, -Markus
