Kernel integrated backports ends in endless silentoldconfig loop when built out of tree

[Gienger Timo <Timo.Gienger@xxxxxxxxxxxxx>]

Hi,

i´m currently having the issue that i´m ending up in an endless loop
with a backports integrated kernel when building out of tree.
When i´m building the Kernel in-tree everything works fine, but when
using "O=" option to build outside of the source tree the build ends up
in an endless loop:

├─(/ssd1/linux-stable)
└─> make O=/ssd1/kout/ 
make[1]: Entering directory `/ssd1/kout'
  GEN     ./Makefile
scripts/kconfig/conf --silentoldconfig Kconfig
make[1]: Leaving directory `/ssd1/kout'
make[1]: Entering directory `/ssd1/kout'
  GEN     ./Makefile
scripts/kconfig/conf --silentoldconfig Kconfig
make[1]: Leaving directory `/ssd1/kout'
make[1]: Entering directory `/ssd1/kout'
  GEN     ./Makefile
scripts/kconfig/conf --silentoldconfig Kconfig
make[1]: Leaving directory `/ssd1/kout'

I´ve tried several combinations:
backports v4.0.1-1 / linux-tree v4.0.1 -> target kernel v3.4.66
backports v3.19.rc1-1 / linux-tree v3.19-rc1 -> target kernel v3.4.66
backports v4.2.2-1 / linux-tree v4.2.2 -> target kernel v4.0
backports v4.4.2-1 / linux-tree v4.4.2 -> target kernel v4.0

But i´m always ending up in the above loop. Of course when i remove the
sourcing of backports in the Kconfig file in the root directory, the out
of tree build works just fine.

I´ve also tried different defconfigs, from x86 to arm cross compiled,
last one i´ve tested was shannon_defconfig.

I was searching the archives, but could not find any issue like that so
far. Anybody tried building it out of tree? Or is that not even meant to
be supported? Or am i doing something completely wrong?

Thanks in advance and BR
Timo

��.n��������+%������w��{.n����i���l