I tried this, which had been working for a decade at least and is documented:

Telcontar:~ # cd /usr/src/linux
Telcontar:/usr/src/linux # make cloneconfig
make[1]: *** No rule to make target 'cloneconfig'.  Stop.
make: *** [Makefile:569: cloneconfig] Error 2
Telcontar:/usr/src/linux # 


The documentation still says to use it:

/usr/share/doc/packages/kernel-source-4.12.14-lp150.12.45/README.SUSE:

�In addition, the running kernel exposes a gzip compressed version of its
configuration file as /proc/config.gz. The kernel sources can be
configured based on /proc/config.gz with ``make cloneconfig''.�


The alternative seems to be:

# cd /usr/src/linux/
# zcat /proc/config.gz > .config
# make silentoldconfig


Then I do:

Telcontar:/usr/src/linux # echo -e "\n-- scripts --" && make scripts && echo -e
"\n-- prepare --" && make prepare && echo -e "\n-- Done good! --"

which fails with:

scripts/mod/modpost.c:26:10: fatal error:
../../include/generated/uapi/linux/suse_version.h: No such file or directory
 #include "../../include/generated/uapi/linux/suse_version.h"
          ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
compilation terminated.


Apparently, the order has to be reversed, firs prepare, then scripts; but the
official documentation has not changed; at "/usr/src/linux/README.SUSE", it
says:

The first method involves the following steps:

  (1)  Install the kernel-source package.

  (2)  Configure the kernel, see HOW TO CONFIGURE THE KERNEL SOURCES.

  (3)  Create files required for compiling external modules:
       ``make scripts'' and ``make prepare''.  <========================

  (4)  Compile the module(s) by changing into the module source directory
       and typing ``make -C $(your_build_dir) M=$(pwd)''.

  (5)  Install the module(s) by typing
       ``make -C $(your_build_dir) M=$(pwd) modules_install''.