Bug#959698: tmux: "incompatible server protocol change" does not seem acceptable

2020-05-04 Thread Romain Francoise
Hi,

On Mon, May 4, 2020 at 10:15 AM Julien Cristau  wrote:
> I don't think that's acceptable.  Running upgrades inside screen or
> tmux is a best practice, so IMO it needs to work, and people need to be
> able to re-attach to existing sessions across the upgrade.

The tmux authors make no promise about the compatibility between new
clients and old servers, and some versions break the protocol. That's
just how it is.

However: in this specific instance, I lazily copied the same NEWS
blurb I always use when the protocol version changes, but upstream
made a deliberate decision *not* to bump the protocol version this
time because the incompatibility issue in 3.1 only affects some
commands (the ones that send data on stdout from the client). It's
possible to attach to an old server from the new client and terminate
it properly, and even if that wasn't the case you could use the old
binary from /proc/pid/exe (which, as I discovered in 2012 in the bug
you linked, is not possible with screen because it's setgid).

So with that in mind, I rephrased the NEWS entry as follows:

https://salsa.debian.org/rfrancoise/tmux/-/commit/15dd27614d659b8cae53c9e5acb54d70f321fcb4

That's the best I can do about this, and I will therefore close this
bug with the upload.

Also, the entire point of adding entries like this to NEWS.Debian is
that apt-listchanges will prompt for confirmation before starting the
upgrade if it's configured properly. Perhaps that configuration should
be more widely documented and encouraged.

Thanks.



Bug#959698: tmux: "incompatible server protocol change" does not seem acceptable

2020-05-04 Thread Julien Cristau
Package: tmux
Version: 3.1-1
Severity: serious

Hi,

on apt upgrade in testing today I was greeted by this NEWS entry from
tmux saying:

  The server protocol was changed in an incompatible manner, we recommend
  that you close any open tmux sessions before proceeding with the upgrade.

I don't think that's acceptable.  Running upgrades inside screen or
tmux is a best practice, so IMO it needs to work, and people need to be
able to re-attach to existing sessions across the upgrade.  And even if
it was acceptable to do this, NEWS.Debian is displayed 1) too late for
the user to do anything about it, 2) in English.

See #683228 for what seems like a similar issue in screen back in the
day.

Cheers,
Julien

-- System Information:
Debian Release: bullseye/sid
  APT prefers unstable-debug
  APT policy: (500, 'unstable-debug'), (500, 'testing-debug'), (500, 
'testing'), (101, 'unstable'), (1, 'experimental')
Architecture: amd64 (x86_64)

Kernel: Linux 5.5.0-2-amd64 (SMP w/8 CPU cores)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8), 
LANGUAGE=en_US:en (charmap=UTF-8)
Shell: /bin/sh linked to /usr/bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled

Versions of packages tmux depends on:
ii  libc6   2.30-4
ii  libevent-2.1-7  2.1.11-stable-1
ii  libtinfo6   6.2-1
ii  libutempter01.1.6-6

tmux recommends no packages.

tmux suggests no packages.

-- no debconf information