[mythtv-users] Frontend crash-restart loop on no backend

[Stephen Worthington]

On Wed, 21 Apr 2021 18:37:17 -0700, you wrote:

>On Mon, Apr 19, 2021, 9:14 PM Stephen Worthington <stephen_agent at jsw.gen.nz>
>wrote:
>
>> On Mon, 19 Apr 2021 18:07:06 -0700, you wrote:
>>
>> >I just had a very frustrating experience that I wanted to report because
>> >I'm sure this couldn't be the intended design.
>> >
>> >I changed my router, which uses a different default gateway, so it hosed
>> >the hard IP address I had coded into the backend.  I mistakenly started
>> the
>> >frontend and it put up a dialog called startup status or something, and of
>> >course it couldn't connect to the backend.
>> >
>> >One of the buttons on that screen is exit. I clicked and confirmed and it
>> >exited. But I got a notification saying the frontend crashed unexpectedly
>> >and would restart, which led me back into the process over and over.
>> >
>> >The restart is not the expected outcome of exiting, and it comes so fast
>> >it's hard to open a terminal window, etc., before it does. I finally
>> >managed, but it was not fun.
>> >
>> >This problem could be eliminated if a normal exit (rather than a crash)
>> >were registered when one hits that exit button.
>>
>> I surmise you are running MythTV on an Ubuntu system.  In Ubuntu, the
>> frontend is a program named "mythfrontend.real", which is run by a
>> script named "mythfrontend".  It is the job of the script to restart
>> mythfrontend.real if it crashes, and as mythfrontend.real does
>> sometimes crash, I find it very useful.  But the script does have a
>> bug which does what you have seen - it does not understand when
>> mythfrontend.real has been shut down, as opposed to crashing.
>>
>> Even when it mythfrontend.real is being restarted all the time, it is
>> usually not a problem to open a terminal if you know how.  But it
>> depends on the system.  If you are running Xubuntu, then you should be
>> able to do Ctrl-Esc to bring up the desktop menu and start a terminal
>> from there.  Due to a recent bug, if it is the first time you are
>> using Ctrl-Esc since booting, you may need to do it twice before you
>> get the menu.  From the menu, go to Applications > Terminal Emulator
>> or Applications > System > Xfce Terminal.  But it does depend on your
>> XFCE version as to where you will find a terminal.
>>
>> And on almost any Linux these days, you can get a text mode terminal
>> by using Ctrl-Alt-F1.  To get back to the GUI screen from there, it is
>> usually Ctrl-Alt-F7 on Ubuntu, but on other systems you may need to
>> try all the Ctrl-Alt-Fx keys.
>>
>> On some systems, Ctrl-Alt-T opens a terminal window, but that may only
>> work when mythfrontend.real is not running.
>>
>> It is also possible to log in from another PC via SSH if you have that
>> enabled.
>>
>
>Yes it it Ubuntu. It never occurred to me to use ctl-alt-f1.  I suppose I
>could also learn not to start the FE before the BE is running!
>
>Since this is a "feature" rather than a bug, I won't post a ticket on it.

No, it is a bug.  The mythfrontend script should be detecting the
difference between mythfrontend.rel being shut down and it crashing or
being killed.  However, that relies on a way of telling the
difference, which may require changes in mythfrontend.real as well as
the mythfrontend script.