[mythtv-users] Mytharchive problems

[Paul Harrison]

SpEnT wrote:
> On 7/3/06, Paul Harrison <mythtv at dsl.pipex.com> wrote:
>   
>> OK, that makes more sense. You need to recompile mytharchive with
>> debugging information then run mytharchivehelper under gdb to get a back
>> trace. Basically do a make distclean then re-run ./configure adding the
>> --compile-type=debug option then compile and install mytharchive as
>> normal. Then  run
>> mytharchivehelper under gdb like this:
>> There's a more detailed description of how to get a bt here
>> http://www.mythtv.org/docs/mythtv-HOWTO-22.html#ss22.2
>>     
>
> Following the instructions from the above link I get(and compiling
> mytharchive with debug on):
>
> (no debugging symbols found)...(no debugging symbols found)...[Thread
> debugging using libthread_db enabled]
> [New Thread 1109785312 (LWP 15266)]
>
> Program received signal SIGSEGV, Segmentation fault.
> [Switching to Thread 1109785312 (LWP 15266)]
> 0x00000029 in ?? ()
>
> Thread 1 (Thread 1109785312 (LWP 15266)):
> #0  0x00000029 in ?? ()
> No symbol table info available.
> #1  0x4144c948 in QMutex::~QMutex () from /usr/lib/qt3/lib/libqt-mt.so.3
> No symbol table info available.
> #2  0x00000000 in ?? ()
> No symbol table info available.
> #3  0x402ee950 in ?? () from /usr/local/lib/libmyth-0.19.so.0
> No symbol table info available.
> #4  0x401fa42d in ErrorCatcher () from /usr/local/lib/libmyth-0.19.so.0
> No symbol table info available.
> #5  0x4193dec8 in __cxa_finalize () from /lib/tls/libc.so.6
> No symbol table info available.
> #6  0x400cc823 in ?? () from /usr/local/lib/libmyth-0.19.so.0
> No symbol table info available.
> #7  0x402cb000 in ?? () from /usr/local/lib/libmyth-0.19.so.0
> No symbol table info available.
> #8  0x0000002e in ?? ()
> No symbol table info available.
> #9  0x0000002f in ?? ()
> No symbol table info available.
> #10 0x40015ff4 in ?? () from /lib/ld-linux.so.2
> No symbol table info available.
> #11 0x40dc122f in ?? ()
> No symbol table info available.
> #12 0x402ee950 in ?? () from /usr/local/lib/libmyth-0.19.so.0
> No symbol table info available.
> #13 0xbffff698 in ?? ()
> No symbol table info available.
> #14 0x40261156 in _fini () from /usr/local/lib/libmyth-0.19.so.0
> No symbol table info available.
> #15 0x40261156 in _fini () from /usr/local/lib/libmyth-0.19.so.0
> No symbol table info available.
> #16 0x4000bfae in _dl_fini () at dl-fini.c:238
>     i = 4
>     l = /root/gdbcommands:7: Error in sourced command file:
> Variable "l" is not available.
>
> Now where it says no debug symbols found I'm assuming it means from
> myth itself so I rebuilt everything with debug: (and only ran it with
> the lines you supplied to get rid of that error)
> # gdb mytharchivehelper
> GNU gdb 6.2-2.1.101mdk (Mandrakelinux)
> Copyright 2004 Free Software Foundation, Inc.
> GDB is free software, covered by the GNU General Public License, and you are
> welcome to change it and/or distribute copies of it under certain conditions.
> Type "show copying" to see the conditions.
> There is absolutely no warranty for GDB.  Type "show warranty" for details.
> This GDB was configured as "i586-mandrake-linux-gnu"...Using host
> libthread_db library "/lib/tls/libthread_db.so.1".
>
> (gdb) run -p out
> Starting program: /usr/local/bin/mytharchivehelper -p out
> [Thread debugging using libthread_db enabled]
> [New Thread 1110407904 (LWP 26327)]
>
> Program received signal SIGSEGV, Segmentation fault.
> [Switching to Thread 1110407904 (LWP 26327)]
> 0x00000029 in ?? ()
> Current language:  auto; currently c
> (gdb) thread apply all bt full
>
> Thread 1 (Thread 1110407904 (LWP 26327)):
> #0  0x00000029 in ?? ()
> No symbol table info available.
> #1  0x41520948 in QMutex::~QMutex () from /usr/lib/qt3/lib/libqt-mt.so.3
> No symbol table info available.
> #2  0x40325fa8 in __JCR_LIST__ () from /usr/local/lib/libmyth-0.19.so.0
> No symbol table info available.
> #3  0x40325fa8 in __JCR_LIST__ () from /usr/local/lib/libmyth-0.19.so.0
> No symbol table info available.
> #4  0x4022acf0 in __tcf_1 () at util-x11.h:22
> No locals.
> #5  0x41a11ec8 in __cxa_finalize () from /lib/tls/libc.so.6
> No symbol table info available.
> #6  0x4010a0c3 in __do_global_dtors_aux () from /usr/local/lib/libmyth-0.19.so.0
> No symbol table info available.
> #7  0x4028da06 in _fini () from /usr/local/lib/libmyth-0.19.so.0
> No symbol table info available.
> #8  0x4000bfae in _dl_fini () at dl-fini.c:238
>         i = 4
>         l = Variable "l" is not available.
>
> --
> Lonny
>   
The segfault is not in mytharchivehelper itself but in the destructor 
for QMutex which is part of QT. Its the extern QMutex x11_lock in 
util-x11.h which is part of  libmyth that is causing the problem. Why 
that is I've no idea I'm afraid :-(

Paul H.