Hello Uwe,
sorry for the "too fast" question,
I found my fault (a missing dependency) myself:
There were these lines (a little bit "hidden" between the many
"CC-lines"):
BTF: .tmp_vmlinux1: pahole (pahole) is not available
Failed to generate BTF for vmlinux
Try to disable CONFIG_DEBUG_INFO_BTF
make[6]: *** [scripts/Makefile.vmlinux:34: vmlinux] Error 1
make[5]: *** [Makefile:1157: vmlinux] Error 2
Salvatore mentioned this too (thank you).
After installing pahole, all went fine (but my CPU needs a long
time for the build process,-)
Need some more time for the next steps.
With regards
Dieter