Re: finding libelf

[Jiri Olsa <jolsa@redhat.com>]

On Wed, Feb 03, 2021 at 12:06:10PM -0800, Andrii Nakryiko wrote:

SNIP

> > > >>
> > > >> but pkg-config tells me:
> > > >>
> > > >> $ pkg-config --modversion  libelf
> > > >> 0.168
> > > >> $ pkg-config --libs  libelf
> > > >> -lelf
> > > >>
> > > >>
> > > >> Any ideas?
> > > >
> > > > This usually happens because there's a stale cache of the feature
> > > > detection tests lying around somewhere. Look for a 'feature' directory
> > > > in whatever subdir you got that error. Just removing the feature
> > > > directory usually fixes this; I've fixed a couple of places where this
> > > > is not picked up by 'make clean' (see, e.g., 9d9aae53b96d ("bpf/preload:
> > > > Make sure Makefile cleans up after itself, and add .gitignore")) but I
> > > > wouldn't be surprised if there are still some that are broken.
> > >
> > > Hi,
> > >
> > > Thanks for replying.
> > >
> > > I removed the feature subdir and still got this build error, so I
> > > removed everything in BUILDDIR/kernel/bpf/preload and rebuilt --
> > > and still got the same libelf build error.
> >
> > I hate the complexity of feature detection framework to the point that
> > I'm willing to rip it out from libbpf's Makefile completely. I just
> > spent an hour trying to understand what's going on in a very similar
> > situation. Extremely frustrating.

I have plans to rework this and get rid of the make code
which is the worst part of that for me.. I'll speed it up ;-)

jirka