#1002544 mpc 0.34 is not compatible with older servers

Package:
mopidy
Source:
mopidy
Submitter:
Nicolas George
Date:
2021-12-31 18:06:04 UTC
Severity:
normal
Tags:
#1002544#5
Date:
2021-12-23 20:05:04 UTC
From:
To:
Dear Maintainer,

mpc 0.34 from Debian Bookworm/sid is not compatible with older versions
of the server or protocol. For example:

cigaes@aimlin ~ $ mpc -h 10.0.1.19 version
warning: MPD 0.21 required
mpd version: 0.19.0
cigaes@aimlin ~ $ mpc -h 10.0.1.19 ls
warning: MPD 0.21 required
MPD error: wrong number of arguments for "tagtypes"
zsh: exit 1     mpc -h 10.0.1.19 ls

(10.0.1.19 is running mopidy 2.2.2-1 from Buster; upgrading it is
desirable but not an option right now.)

Compare with mpc 0.33 on Bullseye:

cigaes@hellroy ~ $ mpc -h 10.0.1.19 ls
Files

If mpc 0.34 cannot be made to work with a 0.19 server, then Debian
should offer the possibility to install mpc 0.33 in parallel, since
users may not control the version of the server they want to connect.

Regards,

#1002544#10
Date:
2021-12-31 17:56:58 UTC
From:
To:
Hi Nicolas,

Thanks for your report.
 > […]

0.19 is quite old, last MPD release in this branch was in 13 Dec 2016 /
v0.19.26. MPD with protocol <0.20 is available in Debian old-old-stable
only (aka stretch).

Well the problem here is mopidy actually. modpidy is stuck with 0.19.0
in master [0], the issue is known though [1].

I understand introducing mpc 0.34 broke with mopidy and it is annoying
in your setup, but mopidy MPD protocol support is partial when not
broken. I've myself stumbled upon issues with it and had to work around
breakage in my own client.

Unfortunately mopidy-mpd plugin need some care.

MPD project is actually leading the development of the protocol, mopidy
should follow. As I wrote, protocol 0.19 is not even in old-stable, I
don't think it's worth shipping mpc 0.33 in parallel (adds confusion for
users and extra work for maintainers).

Let's hope the issue [1] will be dealt with in time for bookworm.

Cheers,
k

[0]
https://github.com/mopidy/mopidy-mpd/blob/master/mopidy_mpd/protocol/__init__.py
[1] https://github.com/mopidy/mopidy-mpd/issues/47

#1002544#15
Date:
2021-12-31 17:56:58 UTC
From:
To:
Hi Nicolas,

Thanks for your report.
 > […]

0.19 is quite old, last MPD release in this branch was in 13 Dec 2016 /
v0.19.26. MPD with protocol <0.20 is available in Debian old-old-stable
only (aka stretch).

Well the problem here is mopidy actually. modpidy is stuck with 0.19.0
in master [0], the issue is known though [1].

I understand introducing mpc 0.34 broke with mopidy and it is annoying
in your setup, but mopidy MPD protocol support is partial when not
broken. I've myself stumbled upon issues with it and had to work around
breakage in my own client.

Unfortunately mopidy-mpd plugin need some care.

MPD project is actually leading the development of the protocol, mopidy
should follow. As I wrote, protocol 0.19 is not even in old-stable, I
don't think it's worth shipping mpc 0.33 in parallel (adds confusion for
users and extra work for maintainers).

Let's hope the issue [1] will be dealt with in time for bookworm.

Cheers,
k

[0]
https://github.com/mopidy/mopidy-mpd/blob/master/mopidy_mpd/protocol/__init__.py
[1] https://github.com/mopidy/mopidy-mpd/issues/47