Kernel build fail with 'btf_encoder__encode: btf__dedup failed!'

["Daniel Xu" <dxu@dxuuu.xyz>]

Hi,

I'm getting the following error during build:

        $ ./tools/testing/selftests/bpf/vmtest.sh -j30
        [...]
          BTF     .btf.vmlinux.bin.o
        btf_encoder__encode: btf__dedup failed!
        Failed to encode BTF
          LD      .tmp_vmlinux.kallsyms1
          NM      .tmp_vmlinux.kallsyms1.syms
          KSYMS   .tmp_vmlinux.kallsyms1.S
          AS      .tmp_vmlinux.kallsyms1.S
          LD      .tmp_vmlinux.kallsyms2
          NM      .tmp_vmlinux.kallsyms2.syms
          KSYMS   .tmp_vmlinux.kallsyms2.S
          AS      .tmp_vmlinux.kallsyms2.S
          LD      .tmp_vmlinux.kallsyms3
          NM      .tmp_vmlinux.kallsyms3.syms
          KSYMS   .tmp_vmlinux.kallsyms3.S
          AS      .tmp_vmlinux.kallsyms3.S
          LD      vmlinux
          BTFIDS  vmlinux
        FAILED: load BTF from vmlinux: No such file or directory
        make[1]: *** [scripts/Makefile.vmlinux:35: vmlinux] Error 255
        make[1]: *** Deleting file 'vmlinux'
        make: *** [Makefile:1264: vmlinux] Error 2

This happens on both bpf-next/master (84150795a49) and 6.2-rc5
(2241ab53cb).

I've also tried arch linux pahole 1:1.24+r29+g02d67c5-1 as well as
upstream pahole on master (02d67c5176) and upstream pahole on
next (2ca56f4c6f659).

Of the above 6 combinations, I think I've tried all of them (maybe
missing 1 or 2).

Looks like GCC got updated recently on my machine, so perhaps
it's related?

        CONFIG_CC_VERSION_TEXT="gcc (GCC) 12.2.1 20230111"

I'll try some debugging, but just wanted to report it first.

Thanks,
Daniel