Error building latest linux kernel within VirtualBox under 18.04.1-Ubuntu - linux-kernel

Question

I am trying to build the latest Linux kernel (GitHub) using a Oracel VM and a 18.04.1-Ubuntu image.
I installed the need packages and probably even more. Here is a part of the packages I installed:
sudo apt-get update
sudo apt-get install git fakeroot build-essential ncurses-dev xz-utils libssl-dev bc bison flex libelf-def kernel-package
The full list can be found here.
I ran the following commands in the linux folder after cloning the repository from GitHub.
$ cp /boot/config-$(uname -r) .config
$ make menuconfig
scripts/kconfig/mconf Kconfig
.config:1118:warning: symbol value 'm' invalid for NF_CT_PROTO_GRE
.config:1923:warning: symbol value 'm' invalid for NET_DEVLINK
.config:7865:warning: symbol value 'm' invalid for ASHMEM
.config:8724:warning: symbol value 'm' invalid for ANDROID_BINDER_IPC
.config:8725:warning: symbol value 'm' invalid for ANDROID_BINDERFS
*** End of the configuration.
*** Execute 'make' to start the build or try 'make help'.
I save and exited menuconfig. And finally make leads to the following error.
$ make -j2
Makefile:608: include/config/auto.conf: No such file or directory
Makefile:660: include/config/auto.conf.cmd: No such file or directory
HOSTCC scripts/kconfig/conf.o
HOSTLD scripts/kconfig/conf
scripts/kconfig/conf --syncconfig Kconfig
*** Error during sync of the configuration.
scripts/kconfig/Makefile:73: recipe for target 'syncconfig' failed
make[2]: *** [syncconfig] Error 1
Makefile:562: recipe for target 'syncconfig' failed
make[1]: *** [syncconfig] Error 2
Makefile:678: recipe for target 'include/config/auto.conf.cmd' failed
make: *** [include/config/auto.conf.cmd] Error 2
make: *** Deleting file 'include/config/auto.conf.cmd'
Looks like make is expecting some additional configuration files include/config/auto.conf. Does anyone have a clue for me.
Thanks!

Answer 1

Trying to compile kernel 5.6.3 as non-root, I ran into this exact problem.
Running the suggestion from Oandiy's comment
git clean -xdf
revealed that I had files in my source tree that were owned by root and could not be deleted. Looking in my history I found,
sudo make localmodconfig # DO NOT DO THIS
which had installed files, as root, in include/config/* and include/generated/autoconf.h.
To see if you have the same problem, run
sudo find . -uid 0
or just look at the error messages of git clean -xdf (there shouldn't be any).
After deleting all files and directories owned by root, I recovered from this deadlock with:
unset ARCH
cp .config ../config.backup # If you still have this.
git clean -xdf # No errors (this also deletes .config)
cp ../config.backup .config # Or generate a new one *).
make olddefconfig # Printed at the end: 'No change to .config'
Note that I needed to clear ARCH from my environment.
After this I went on as usual,
VERSION=5.6.3 # I have checked out tag v5.6.3 **)
FLAVOUR=lowlatlocxhci # Or whatever you want to call your kernel.
make -j8 deb-pkg LOCALVERSION=-$FLAVOUR
sudo dpkg -i ../linux-headers-$VERSION-${FLAVOUR}_$VERSION-$FLAVOUR-1_amd64.deb ../linux-image-$VERSION-${FLAVOUR}_$VERSION-${FLAVOUR}-1_amd64.deb
The last command fails to compile virtualbox kernel modules at the moment, but I don't care about those, and those errors can be ignored (as long as you don't use virtual box).
*) The .config used was prepared by booting to a kernel with everything (ie, a dist. kernel), copying its config from /boot to the source tree and running make localmodconfig after making sure all kernel modules that I needed where loaded (by running those applications that cause such modules to be loaded). And finally running make menuconfig to turn off CONFIG_DEBUG_INFO in this kernel and to turn a few things that are normally built into the kernel into modules as well (which I needed for some reason).
**) My git tree has been prepared with:
VERSION=5.6.3
FLAVOUR=lowlatlocxhci
git clone git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git linux-$VERSION-$FLAVOUR-$VERSION-$FLAVOUR
cd linux-$VERSION-$FLAVOUR-$VERSION-$FLAVOUR
git checkout -b test_$FLAVOUR v$VERSION
# Make manual changes here, and commit as usual.