Tvheadend

I am trying to compile actual version from git but I get the following error during compilation:

In file included from /root/src/tvheadend/build.linux/ffmpeg/build/ffmpeg/include/libavutil/common.h:488,
                 from /root/src/tvheadend/build.linux/ffmpeg/build/ffmpeg/include/libavutil/avutil.h:296,
                 from /root/src/tvheadend/build.linux/ffmpeg/build/ffmpeg/include/libavutil/samplefmt.h:24,
                 from /root/src/tvheadend/build.linux/ffmpeg/build/ffmpeg/include/libavcodec/avcodec.h:31,
                 from /root/src/tvheadend/build.linux/ffmpeg/build/ffmpeg/include/libavformat/avformat.h:319,
                 from src/libav.h:26,
                 from src/tvhlog.c:35:
/root/src/tvheadend/build.linux/ffmpeg/build/ffmpeg/include/libavutil/mem.h:342:1: error: ‘alloc_size’ attribute ignored on a function returning ‘int’ [-Werror=attributes]
  342 | av_alloc_size(2, 3) int av_reallocp_array(void *ptr, size_t nmemb, size_t size);
      | ^~~~~~~~~~~~~
cc1: all warnings being treated as errors
make: *** [Makefile:717: /root/src/tvheadend/build.linux/src/tvhlog.o] Fehler 1
make: *** Es wird auf noch nicht beendete Prozesse gewartet....
In file included from /root/src/tvheadend/build.linux/ffmpeg/build/ffmpeg/include/libavutil/common.h:488,
                 from /root/src/tvheadend/build.linux/ffmpeg/build/ffmpeg/include/libavutil/avutil.h:296,
                 from /root/src/tvheadend/build.linux/ffmpeg/build/ffmpeg/include/libavutil/samplefmt.h:24,
                 from /root/src/tvheadend/build.linux/ffmpeg/build/ffmpeg/include/libavcodec/avcodec.h:31,
                 from /root/src/tvheadend/build.linux/ffmpeg/build/ffmpeg/include/libavformat/avformat.h:319,
                 from src/libav.h:26,
                 from src/main.c:70:
/root/src/tvheadend/build.linux/ffmpeg/build/ffmpeg/include/libavutil/mem.h:342:1: error: ‘alloc_size’ attribute ignored on a function returning ‘int’ [-Werror=attributes]
  342 | av_alloc_size(2, 3) int av_reallocp_array(void *ptr, size_t nmemb, size_t size);
      | ^~~~~~~~~~~~~
cc1: all warnings being treated as errors
make: *** [Makefile:716: /root/src/tvheadend/build.linux/src/main.o] Fehler 1

I am using Debian Testing (Debian GNU/Linux bullseye/sid) and use gcc version 9.2.1 20190909 (Debian 9.2.1-8).

Compilation is done with the following commands:

./configure --enable-vaapi
make -j 4

Latest version which can be compiled is: tvheadend_4.3-1804~gebb096804.