Hello guix,

Does anyone has the same problem with ffmpeg from latest master? I've
got the following error:

========================================================================
alexvong1995@debian:~$ ffmpeg --help
ffmpeg: error while loading shared libraries: /gnu/store/4hcr7ygdhaxws6q5dj806cbvq0dkfgkw-ffmpeg-4.1.1/lib/libavdevice.so.58: file too short
========================================================================

The following command shows that most of the shared libraries built are
empty:

========================================================================
alexvong1995@debian:~$ LC_ALL=C find "$(guix build ffmpeg)/lib" -type f -execdir ls -hl '{}' ';'
-r-xr-xr-x 26 root root 0 Jan  1  1970 ./libavformat.so.58.20.100
-r-xr-xr-x 26 root root 0 Jan  1  1970 ./libavutil.so.56.22.100
-r--r--r-- 6785 root root 0 Jan  1  1970 ./libavfilter.pc
-r--r--r-- 6785 root root 0 Jan  1  1970 ./libavutil.pc
-r--r--r-- 6785 root root 0 Jan  1  1970 ./libavresample.pc
-r--r--r-- 6785 root root 0 Jan  1  1970 ./libpostproc.pc
-r--r--r-- 6785 root root 0 Jan  1  1970 ./libswresample.pc
-r--r--r-- 6785 root root 0 Jan  1  1970 ./libavcodec.pc
-r--r--r-- 6785 root root 0 Jan  1  1970 ./libavformat.pc
-r--r--r-- 6785 root root 0 Jan  1  1970 ./libswscale.pc
-r--r--r-- 6785 root root 0 Jan  1  1970 ./libavdevice.pc
-r-xr-xr-x 26 root root 0 Jan  1  1970 ./libavdevice.so.58.5.100
-r-xr-xr-x 26 root root 0 Jan  1  1970 ./libavfilter.so.7.40.101
-r-xr-xr-x 26 root root 0 Jan  1  1970 ./libavresample.so.4.0.0
-r-xr-xr-x 26 root root 0 Jan  1  1970 ./libswresample.so.3.3.100
-r-xr-xr-x 26 root root 0 Jan  1  1970 ./libpostproc.so.55.3.100
-r-xr-xr-x 26 root root 0 Jan  1  1970 ./libswscale.so.5.3.100
-r-xr-xr-x 2 root root 14M Jan  1  1970 ./libavcodec.so.58.35.100
========================================================================

I'm CC'ing guix-devel since ffmpeg is essential to many audio/video
packages (e.g. mpv, vlc).

Cheers,
Alex