Bug#826098: fakeroot make -f debian/rules.gen binary-arch_powerpc_none_powerpc

[Mathieu Malaterre <malat@debian.org>]

Package: src:linux
Version: 4.5.5-1

I am starring at the documentation for rebuilding the Debian kernel.
I'd like to test a change in a non-module section of the kernel code
(CONFIG_FB_OF=y), to resolve #825840. So I thought I could simply
follows the steps from:

https://kernel-handbook.alioth.debian.org/ch-common-tasks.html#s4.2.5

[...]
# apt-get install build-essential fakeroot
# apt-get build-dep linux
$ mkdir tmp && cd tmp
$ apt-get source linux-image-$(uname -r)
$ cd linux-*
$ fakeroot debian/rules source
$ fakeroot make -f debian/rules.gen binary-arch_powerpc_none_powerpc
[...]
dh_installdocs
dh_installchangelogs
dh_strip
Can't exec "-objcopy": No such file or directory at
/usr/share/perl5/Debian/Debhelper/Dh_Lib.pm line 243.
dh_strip: -objcopy --only-keep-debug --compress-debug-sections
debian/linux-image-4.5.0-2-powerpc/usr/lib/linux-image-4.5.0-2-powerpc/hack-coff
debian/.debhelper/linux-image-4.5.0-2-powerpc/dbgsym-root/usr/lib/debug/.build-id/db/692a8d7808bd1b2adc58cd43f114d6fe006303.debug
failed to to execute: No such file or directory
debian/rules.real:194: recipe for target 'install-base' failed
make[2]: *** [install-base] Error 2
make[2]: Leaving directory '/home/mathieu/tmp/linux-4.5.4'
debian/rules.real:376: recipe for target
'install-image_powerpc_none_powerpc' failed
make[1]: *** [install-image_powerpc_none_powerpc] Error 2
make[1]: Leaving directory '/home/mathieu/tmp/linux-4.5.4'
debian/rules.gen:204: recipe for target
'binary-arch_powerpc_none_powerpc_real' failed
make: *** [binary-arch_powerpc_none_powerpc_real] Error 2

I can see objcopy right here:

mathieu@debian:~/tmp/linux-4.5.4$ ls -al /usr/bin/*objcopy
lrwxrwxrwx 1 root root     25 May 12 16:59 /usr/bin/objcopy ->
powerpc-linux-gnu-objcopy
-rwxr-xr-x 1 root root 266200 May 12 16:59 /usr/bin/powerpc-linux-gnu-objcopy

And I am using:

mathieu@debian:~/tmp/linux-4.5.4$ uname -a
Linux debian 4.5.0-2-powerpc #1 Debian 4.5.4-1 (2016-05-16) ppc GNU/Linux

Does anyone know how to build only the powperpc flavor from a powerpc system ?

Thanks much.