Re: [bpf-next:master 8/9] FAILED: load BTF from .tmp_vmlinux1.BTF.1: No such file or directory

[Ihor Solodrai <ihor.solodrai@linux.dev>]

On 12/24/25 5:01 PM, kernel test robot wrote:
> tree:   https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git master
> head:   f14cdb1367b947d373215e36cfe9c69768dbafc9
> commit: 522397d05e7d4a7c30b91841492360336b24f833 [8/9] resolve_btfids: Change in-place update with raw binary output
> config: nios2-randconfig-001-20251224 (https://download.01.org/0day-ci/archive/20251225/202512250932.X7mdviuH-lkp@intel.com/config)
> compiler: nios2-linux-gcc (GCC) 11.5.0
> reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20251225/202512250932.X7mdviuH-lkp@intel.com/reproduce)
> 
> If you fix the issue in a separate patch/commit (i.e. not just a new version of
> the same patch/commit), kindly add following tags
> | Reported-by: kernel test robot <lkp@intel.com>
> | Closes: https://lore.kernel.org/oe-kbuild-all/202512250932.X7mdviuH-lkp@intel.com/
> 
> All errors (new ones prefixed by >>):
> 
>    Complex, interval and imaginary float types are not supported
>    Error while encoding BTF.

Hi Dinh, Alan,

Not sure why this has surfaced only now, but it appears that kernel
build with ARCH=nios2 and CONFIG_DEBUG_INFO_BTF=y has been broken for
a long time.

I tried the following revisions:
  - bpf-next @ 522397d05e7d as in bug report
  - bpf-next @ 014e1cdb5fad without the gen-btf.sh patch
  - v6.18
  - v6.17
  - v6.12 (~1y ago)

All fail with the same error in pahole [1]:

	Complex, interval and imaginary float types are not supported
	Encountered error while encoding BTF.

I used v1.24 in most experiments, the default debian:bookworm
installation.  Upgrading pahole to v1.31 doesn't change this behavior.

I also stumbled on a phoronix article [2], saying Nios II support has
ended with GCC 15. Is it actively supported in Linux?

Not clear to me if anything needs to be fixed here. I'd appreciate any input.

Thanks.

[1] https://git.kernel.org/pub/scm/devel/pahole/pahole.git/tree/btf_encoder.c?h=v1.31#n469
[2] https://www.phoronix.com/news/GCC-15-Drops-Altera-Nios-II


>>> FAILED: load BTF from .tmp_vmlinux1.BTF.1: No such file or directory
>