[mythtv-users] Caveats in upgrading from Ubuntu 18.04 + MythTV 29.1 to something newer?

[Stephen Worthington]

On Thu, 9 Mar 2023 18:27:06 -0500, you wrote:

>Hi folks,
>
>I'm a strong believer in "If it ain't broke, don't fix it!"
>But at the same time I also don't want to be running 
>unsupported/vulnerable platforms.  And it's touch hard to reconcile 
>these two different mindsets.
>
>Given the upcoming EOL of Ubuntu 18.04, I figure that it's time to 
>update things.  But before I dig into this project, I'm curious about 
>any snags that one might expect in either the updating of a MythTV box's 
>underlying Ubuntu version, or the updating of MythTV itself.
>
>Having skimmed through this list from time to time, I seem to recall 
>seeing messages along the line of "lirc doesn't work anymore unless you 
>do <blah>", or something similar.
>
>Is there a resource out there that covers the various things that may 
>break as the result of doing such an update (both MythTV and Ubuntu, if 
>I had my wishes), and what can be done to prevent/correct them? 
>Obviously I'll have a full system backup before going down this path, 
>but I'd like to avoid surprises and the related time sinks.
>
>
>Thanks
>-WD

I am afraid that there is no specific resource where all the
accumulated knowledge about update problems resides.  This list and
the forum will have what you need, but finding it will be a problem.
The upside of waiting so long to upgrade is that all the problems you
might encounter should already have been met by other people and
solved already.

If you have not already upgraded the PC to use SSD for the operating
system, it is best to do that before upgrading the Ubuntu version, as
without SSD the upgrade times would be pretty bad now.  Especially as
you will need to do two upgrades - 18.04 to 20.04 and then 20.04 to
22.04.

When I do an Ubuntu version upgrade, there are always config files
that the upgrade process flags as having been altered from the
standard version, and the upgrade pauses on each one to ask what you
want to do about it (keep the old one, or use the new one, or manually
fix the problem).  I use a GUI diff program (vsdiff that comes with my
pay Slickedit editor) to compare the old and new files and create a
merged version.  Most of the time, the changes are obvious and I just
have to copy things from the either version of the file appropriately.
I would recommend that you find yourself a good GUI diff program and
try it out before doing the upgrades.

About lirc specifically, I believe the "lirc does not work" problem is
fixed in 22.04 (the missing _client.so file is present), but you may
still need to update your lirc config for it to work properly.  You
should not use the lirc_setup program though, as it accidentally
somehow deletes the _client.so file, so you need to manually set up
the /etc/lirc/lirc_options.conf file.  Should the _client.so file be
deleted, you can just reinstall it by using this command:

sudo apt install --reinstall lirc

I think the major updates to lirc happened in the 16.04 to 18.04
upgrade (the drivers moved into the kernel mostly), so your 18.04
setup should only need tweaks rather than anything major.  If you have
customised your keymap files in /etc/rc_keymaps, then they will need
to be converted to the new .toml format.  See
/usr/lib/udev/rc_keymaps/ for the standard .toml keymap files that you
can copy and modify.  It is only a format change, the content in the
files is the same.  And if you are using
/etc/lirc/lircd.conf.d/devinput.lircd.conf to configure the remote
keystrokes, the new lirc has slightly updated versions in each Ubuntu
upgrade, usually to add new keystrokes, but some have been renamed
occasionally.  I just run a diff between the new and old versions and
it is usually clear what changes are needed.  Then you may need to
change your $(HOME)/<mythfrontend user>/.lircrc/mythtv file to match
any changed names in devinput.lircd.conf.

For mythweb, each new version of Ubuntu updates the PHP version, so
you need to make sure you change your Apache2 config to use the new
version.  This does not happen automatically.  To do this for php8.1
in Ubuntu 22.04:

sudo a2query -m | grep php

to see the currently enabled php module version and then:

sudo a2dismod php<old-version-number>
sudo a2enmod php8.1
sudo systemctl restart apache2