Tvheadend

Do you have tvhomerun tuner ?

No. Its a Hauppauge HVR-2250. I did have the hdhomerun packages installed on my system though. I have uninstalled them.

Do you have timeshift enabled?

Timeshift has never been enabled.

Really no idea. These things are most difficult to debug. I plan to add some memory allocation statistics.

Well, like I said it does it out of the blue. I have been using various versions of tvheadend for about a year and a half and it has happened maybe ten times. I am a programmer myself (PHP) and understand how difficult some bugs are to debug. I do believe the bug has been there for a long time.

Perhaps, you may try to run tvheadend through valgrind:

cd git/tvheadend
valgrind --leak-check=full --show-reachable=yes ./build.linux/tvheadend

Do the scan on all muxes and then press Ctrl-C in the console with valgrind if it shows something.

I am now running the program through valgrind as per your instructions to try and find this memory leak. I haven't done this before so I don't know what kind of resource usage we are talking here or if my computer can handle it. I guess only time will tell. Even if my computer can handle it, it may be a while before it gives me any memory issues. I remember it happening after a program had finished auto-recording possibly right before the next one started, however the next program which was supposed to record never showed up in the log.