[mythtv-users] Masterbackend segfault when creating preview

[Bill Meek]

On 12/15/2012 09:41 AM, John Nissley wrote:
...
 > Problem
> As I continued to try to figure out what is happening I noticed that I would often get a masterbackend segfault when exiting a recording. I see
> the following error in my previewgen log file very often:
>   mythpreviewgen[22833]: E CoreContext main.cpp:97 (preview_helper) Setting priority failed.
>                          eno: Permission denied (13)
> I have checked permissions on everything I can think of and I am running my backends as user mythtv and not root.  I also noticed that the
> preview ping files now show up in the frontend user home directory.  Not sure when that started but I assume it is because different front ends
> could be at different places in a recording.
>
> And direction from the list to help me resolve this issue would be appreciated.

Hi;

The permission problem is caused by the setpriority() call failing. In:
man setpriotiry, there's some detail regarding kernel versions. Your
file permissions aren't the issue.
     http://code.mythtv.org/cgit/mythtv/tree/mythtv/programs/mythpreviewgen/main.cpp#n95

As to the segfaults, this Wiki is pretty good:
    http://www.mythtv.org/wiki/Debugging#Basic_backtrace.

Maybe you could pastebinit the entire log from a single failing run of
mythpreviewgen (for the .png file issue you mentioned.)
    http://www.mythtv.org/wiki/Posting_Logs.

-- 
Bill