Bug#693040: libav: Strange build failure on several archs

[Reinhard Tartler <siretart@debian.org>]

Package: libav
Version: 6:9~beta2-2
Severity: important
Tags: help

I require assistance from a toolchain savy expert. I have uploaded a new
upstream version of libav to experimental. Unfortunately, it fails to
build on several architectures with the following error:


gcc -Llibavcodec -Llibavdevice -Llibavfilter -Llibavformat -Llibavresample -Llibavutil -Llibswscale -Wl,-z,relro  -Wl,--as-needed -Wl,--warn-common -Wl,-rpath-link=libswscale:libavfilter:libavdevice:libavformat:libavcodec:libavutil:libavresample  -o avconv avconv_opt.o avconv_filter.o avconv.o cmdutils.o  -lavdevice -lavfilter -lavformat -lavresample -lavcodec -lswscale -lavutil -ldl -ldl -lXfixes -lXext -lX11 -lcdio_paranoia -lcdio_cdda -lcdio -ljack -lasound -ldc1394 -lraw1394 -lgcrypt -lxvidcore -lx264 -lvpx -lvpx -lvorbisenc -lvorbis -logg -ltheoraenc -ltheoradec -logg -lspeex -lschroedinger-1.0 -lrtmp -lz -lgnutls -lpulse-simple -lpulse -lopenjpeg -lopencv_core -lopencv_imgproc -lopencv_highgui -lopencv_ml -lopencv_video -lopencv_features2d -lopencv_calib3d -lopencv_objdetect -lopencv_contrib -lopencv_legacy -lopencv_flann -lmp3lame -lgsm -lfreetype -lgnutls -lva -lm -pthread -lbz2 -lz  
libavfilter/libavfilter.so: undefined reference to `ff_log2_tab'
collect2: ld returned 1 exit status
make[1]: *** [avconv] Error 1

See https://buildd.debian.org/status/package.php?p=libav&suite=experimental


I don't get it. The symbol ff_log2_tab is defined in this file:
http://anonscm.debian.org/gitweb/?p=pkg-multimedia/libav.git;a=blob;f=libavutil/log2_tab.c,
and libavutil is being linked into the library. Moreover, only armel,
s390, s390x and sparc are affected.

I've tried to reproduce the problem in the porter sid chroot on
zelenka.debian.org, but was not able to reproduce the situation. All
archs also seem to have the same version of binutils/gcc.

Can anyone please help me out here?


-- 
Gruesse/greetings,
Reinhard Tartler, KeyID 945348A4