After disabled CONFIG_DEBUG_INFO, stop background tasts, the second build finished in
about 1 hour.
The result kernel installed OK but failed to boot.
$ du -a
1288 ./kernel-headers-5.14.0_custom_437467a359f+-2.x86_64.rpm
83120 ./kernel-5.14.0_custom_437467a359f+-2.x86_64.rpm
Do I need to build the kernel-modules and kernel-core as well?