Bug#1125774: ndpi: FTBFS on arm64: missing symbol

[Adrian Bunk]

On Sun, Jan 18, 2026 at 06:53:36PM +0100, Andreas Metzler wrote:
> On 2026-01-18 Adrian Bunk <bunk at debian.org> wrote:
> > Control: reassign -1 libgcrypt20 1.11.2-3
> 
> > On Sun, Jan 18, 2026 at 07:28:22AM +0100, Andreas Metzler wrote:
> > > Control: reassign 1125774 ndpi 4.2-2.1
> > > 
> > > On 2026-01-17 Emanuele Rocca <ema at debian.org> wrote:
> [...]
> > > > What's happening is that configure.ac uses AC_LANG_WERROR, which means
> > > > compiler warnings are considered errors:
> > > > https://sources.debian.org/src/ndpi/4.2-2.1/configure.ac#L45
> > > 
> > > > That's why suppressing the GCS warning fixes the build, as Adrian found.
> > > 
> > > Ah, thank you.
> > > 
> > > Let's reassign back to ndpi then.
> 
> > Why does ld complain about libgcrypt not having GCS enabled
> > (as said already during the build of libgcrypt20)?
> 
> > This is the root cause, that should be fixed unless there is a good 
> > reason not to do so.
> 
> > Emanuele might be better qualified to understand why this happens.
> 
> Eh.
> 
> We have
> 1) GCS is an optional feature. dpkg-buildflags now enables it by default
> on arm64 but gcc only warns when this does not succeed.
> 2) libgcrypt is not yet supporting it (I suspect because there is asm in play)
> 3) ndpi FTBFS because of AC_LANG_WERROR.
> 
> I cannot see how this can be more than a minor or wishlist bug in
> libgcrypt and a serious bug in ndpi as long as GCS is an optional
> feature.[1] So 1125774 should be against ndpi.
> 
> I do not intend to play reassigning ping-pong. - Please re-assign back
> if you consider my rationale convincing.

My thinking here is about trying to understand the root cause first,
and then continue from that. With all initial information and discussion
in one bug.

ndpi only failed much later due to a missing symbol, this might just be 
the tip of a much larger iceberg of packages that silently get compiled 
differently on arm64 the next time they get rebuilt.

If possible this should be fixed in libgcrypt20, and then there is 
nothing to do in ndpi.

If this is for some reason not (easily) possible, then a bug setup as 
you suggest makes sense.

> cu Andreas
>...

cu
Adrian