[Pkg-mpd-maintainers] Bug#887834: mpd installation fails, cannot open /var/lib/mpd/tag_cache, /run/mpd/pid

[Guillaume]

Package: mpd
Version: 0.20.14-1

When attempting to install the mpd package from Debian testing, it fails
with the following errors:

> Setting up mpd (0.20.14-1) ...
> Job for mpd.service failed because the control process exited with error code.
> See "systemctl status mpd.service" and "journalctl -xe" for details.
> invoke-rc.d: initscript mpd, action "start" failed.
> ● mpd.service - Music Player Daemon
>    Loaded: loaded (/lib/systemd/system/mpd.service; disabled; vendor preset: enabled)
>    Active: failed (Result: exit-code) since Sat 2018-01-20 12:37:07 CET; 16ms ago
>      Docs: man:mpd(1)
>            man:mpd.conf(5)
>            file:///usr/share/doc/mpd/user-manual.html
>   Process: 5411 ExecStart=/usr/bin/mpd --no-daemon $MPDCONF (code=exited, status=1/FAILURE)
>  Main PID: 5411 (code=exited, status=1/FAILURE)
> 
> Jan 20 12:37:06 sark systemd[1]: Starting Music Player Daemon...
> Jan 20 12:37:07 sark mpd[5411]: Jan 20 12:37 : exception: Failed to open /var/lib/mpd/tag_cache: No such file or directory
> Jan 20 12:37:07 sark mpd[5411]: Jan 20 12:37 : fatal_error: Failed to create pid file "/run/mpd/pid": No such file or directory
> Jan 20 12:37:07 sark systemd[1]: mpd.service: Main process exited, code=exited, status=1/FAILURE
> Jan 20 12:37:07 sark systemd[1]: mpd.service: Failed with result 'exit-code'.
> Jan 20 12:37:07 sark systemd[1]: Failed to start Music Player Daemon.
> dpkg: error processing package mpd (--configure):
>  installed mpd package post-installation script subprocess returned error exit status 1