Arch Linux

Description:

I just installed Thunderbird package version 52.6.0-2.
When trying to run it, I just get the following error:

$ thunderbird
XPCOMGlueLoad error for file /usr/lib/thunderbird/libxul.so:
libvpx.so.5: cannot open shared object file: No such file or directory
Couldn't load XPCOM.

Indeed:

$ ldd /usr/lib/thunderbird/libxul.so | grep vpx
libvpx.so.5 => not found

I do, however, have libvpx.so.4:

$ find /usr -name libvpx*
/usr/lib/vlc/plugins/codec/libvpx_plugin.so
/usr/lib/libvpx.so
/usr/lib/libvpx.so.4
/usr/lib/libvpx.so.4.1
/usr/lib/libvpx.so.4.1.0
...

And it is owned by this libvpx package:

$ pacman -Fo /usr/lib/libvpx.so.4
usr/lib/libvpx.so.4 is owned by extra/libvpx 1.6.1-1

I tried to "sudo pacman -S libvpx" but it won't let me do it
(it says that this would break a dependency on ffmpeg, which in
turn would remove half a dozen applications that I need).

I'm fairly new to ArchLinux and I don't know what I sould try next,
so I'm open to suggestions! :-)

Thanks.