Re: [BUG] bpftool: Build failure due to opensslv.h

[Namhyung Kim <namhyung@kernel.org>]

On Mon, Oct 27, 2025 at 11:41:01AM +0000, Quentin Monnet wrote:
> 2025-10-26 21:01 UTC-0700 ~ Namhyung Kim <namhyung@kernel.org>
> > Hello,
> > 
> > I'm seeing a build failure like below in Fedora 40 and others.  I'm not
> > sure if it's reported already but it failed to build perf tools due to
> > errors in the bootstrap bpftool.
> > 
> >     CC      /build/util/bpf_skel/.tmp/bootstrap/sign.o
> >   sign.c:16:10: fatal error: openssl/opensslv.h: No such file or directory
> >      16 | #include <openssl/opensslv.h>
> >         |          ^~~~~~~~~~~~~~~~~~~~
> >   compilation terminated.
> >   make[3]: *** [Makefile:256: /build/util/bpf_skel/.tmp/bootstrap/sign.o] Error 1
> >   make[3]: *** Waiting for unfinished jobs....
> >   make[2]: *** [Makefile.perf:1213: /build/util/bpf_skel/.tmp/bootstrap/bpftool] Error 2
> >   make[1]: *** [Makefile.perf:289: sub-make] Error 2
> >   make: *** [Makefile:76: all] Error 2
> > 
> > I think it's from the recent signing change.  I'm not familiar with
> > openssl but I guess there's a proper feature check for it.  Is this a
> > known issue?
> 
> 
> Hi Namhyung,

Hello!

> 
> This looks related to the program signing change indeed, commit
> 40863f4d6ef2 ("bpftool: Add support for signing BPF programs")
> introduced a dependency on OpenSSL's development headers for bpftool.
> It's not gated behind a feature check. On Fedora, I think the headers
> come with openssl-devel, do you have this package installed?

No I don't, but I guess it should be able to build on such systems.  Or
is it required for bpftool?  Anyway I feel like it should have a feature
check and appropriate error messages.

Thanks,
Namhyung