[mythtv-users] Segfault while tuning channel in mythtv 31.0

[David Hampton]

On Fri, 2020-07-17 at 14:26 +0200, Thomas Börkel wrote:
> Hi all,
> 
> I just upgraded from mythtv 30.0 to 31.0 (fixes) on Gentoo and now I
> get
> a segfault when it is tuning a channel.
> 
> Happens when EIT scan starts or when I start Live TV. Did not test
> recording yet.
> 
> Output in gdb for Live TV:
> 
> Thread 8 "TVRecEvent" received signal SIGSEGV, Segmentation fault.
> [Switching to Thread 0x7fe57b7fe700 (LWP 30677)]
> 0x00007fe5a4651a6c in ?? () from /usr/lib64/libmythtv-31.so.31
> 
> Attaching full gdb.txt.
> 
> After upgrading, I went into mythtv-setup and noticed that the
> "DVBInput" is configured as capture cards delivery system, which is
> not
> an option in the select box. So, I changed that to "DVB-S2". But that
> did not change anything regarding the crash.
> 
> Any hints would be greatly appreciated.

I'm assuming that everything before line 480 is old cruft as it
reference a Qt4 library.  Qt4 hasn't been supported since 0.27.  If
those aren't old stack traces, start there. Current MythTV requires
Qt5.

The last stack frame in the file crashed here:

Thread 8 (Thread 0x7fe57b7fe700 (LWP 30677)):
#0  0x00007fe5a4651a6c in  () at /usr/lib64/libmythtv-31.so.31
#1  0x00007fe5a46523cf in  () at /usr/lib64/libmythtv-31.so.31
#2  0x00007fe5a465c036 in  () at /usr/lib64/libmythtv-31.so.31
#3  0x00007fe5a448966d in  () at /usr/lib64/libmythtv-31.so.31
#4  0x00007fe5a4531371 in TVRec::SetupSignalMonitor(bool, bool, bool)
() at /usr/lib64/libmythtv-31.so.31
#5  0x00007fe5a45384f0 in TVRec::TuningFrequency(TuningRequest const&)
() at /usr/lib64/libmythtv-31.so.31
#6  0x00007fe5a453d63c in TVRec::HandleTuning() () at
/usr/lib64/libmythtv-31.so.31
#7  0x00007fe5a453da67 in TVRec::run() () at /usr/lib64/libmythtv-
31.so.31
#8  0x00007fe5a3afc887 in MThread::run() () at /usr/lib64/libmythbase-
31.so.31
#9  0x00007fe5a27aaf4c in  () at /usr/lib64/libQt5Core.so.5
#10 0x00007fe5a36c9f27 in start_thread () at /lib64/libpthread.so.0
#11 0x00007fe5a2393b7f in clone () at /lib64/libc.so.6

This looks wrong as gdb should have names for all the functions in
libmythtv-31. Is this a stripped image? Can you build an image with
debug symbols still present? That would be extremely helpful.

David