mythtv-setup.real crashed with SIGSEGV in QVariant::QVariant()

[Fabián Rodríguez]

When trying to setup MythTV, after starting theMythTV Backend configuration utility, it crashes after country selection (language choice is never displayed).

ProblemType: Crash
DistroRelease: Ubuntu 12.04
Package: mythtv-backend 2:0.24.0+fixes.20111207.40f3bae-0ubuntu1
ProcVersionSignature: Ubuntu 3.2.0-5.11-generic 3.2.0-rc5
Uname: Linux 3.2.0-5-generic x86_64
NonfreeKernelModules: nvidia wl
ApportVersion: 1.90-0ubuntu1
Architecture: amd64
CrashCounter: 1
Date: Sun Dec 18 02:10:37 2011
ExecutablePath: /usr/bin/mythtv-setup.real
InstallationMedia: Ubuntu 12.04 LTS "Precise Pangolin" - Alpha amd64 (20111217)
Installed_mythtv_dbg: 0.0
ProcCmdline: /usr/bin/mythtv-setup.real
ProcEnviron:
 PATH=(custom, no user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SegvAnalysis:
 Segfault happened at: 0x7f48dd8fb0f6 <_ZN8QVariantC2ERKS_+22>: mov (%rsi),%rcx
 PC (0x7f48dd8fb0f6) ok
 source "(%rsi)" (0x00000038) not located in a known VMA region (needed readable region)!
 destination "%rcx" ok
SegvReason: reading NULL VMA
Signal: 11
SourcePackage: mythtv
StacktraceTop:
 QVariant::QVariant(QVariant const&) () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4
 MythUIButtonListItem::GetData() () from /usr/lib/libmythui-0.24.so.0
 LanguageSelection::Save() () from /usr/lib/libmyth-0.24.so.0
 LanguageSelection::qt_metacall(QMetaObject::Call, int, void**) () from /usr/lib/libmyth-0.24.so.0
 QMetaObject::activate(QObject*, QMetaObject const*, int, void**) () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4
Title: mythtv-setup.real crashed with SIGSEGV in QVariant::QVariant()
UpgradeStatus: No upgrade log present (probably fresh install)
UserGroups: adm cdrom dip lpadmin mythtv plugdev sambashare sudo

[MarcRandolph (mrand)]

Howdy, and thank you for helping to improve Mythbuntu by opening this ticket. Was this crash reproducible for you, or did you try again and get past that point? Unfortunately, through no fault of your own, it appears that the debugging information that was captured is invalid, so we will likely have to close this ticket.

[Mario Limonciello (superm1)]

specifically if it is reproducible it would be quite helpful to install mythtv-dbg before reproducing it and filing another apport bug.

[B.B. Lauret (bblauret)]

Same here in up-to-date precise:
Program received signal SIGSEGV, Segmentation fault.
0x02020d9b in QVariant::QVariant(QVariant const&) () from /usr/lib/i386-linux-gnu/libQtCore.so.4
quit

Also the same segfault with the mythbuntu 0.24 ppa.

[MarcRandolph (mrand)]

Marking as confirmed since there is a second report - but we really need a backtrace for this ticket to go anywhere.

[B.B. Lauret (bblauret)]

Is this backtrace any help? If not, please point me to the right way, as I do not have any prior experience creating backtraces.

I should add I have not found a way to use apport, as I am running this on a headless server using X-redirection over ssh. I do not have X on the server. Mythtv is installed using the mythtv-backend-master meta-package. Should I use `ubuntu-bug -c /var/crash/_usr_bin_mythtv-setup.real.1000.crash -u 905886` ?

[pdf (pdffs)]

libmyth-0.24-0-2:0.24.2+fixes.20120127.10d5624-0ubuntu0mythbuntu2
mythtv-backend-2:0.24.2+fixes.20120127.10d5624-0ubuntu0mythbuntu2
mythtv-backend-master-2:0.24.2+fixes.20120127.10d5624-0ubuntu0mythbuntu2

Full backtrace with relevant symbols.

[pdf (pdffs)]

Okay, this is a packaging problem - /usr/share/mythtv/i18n/mythfrontend* needs to be split out from mythfrontend, put into a separate package, and both mythtv-backend and mythtv-frontend then need to depend on it. In the short term, installing mythtv-frontend allows mythtv-setup to work.

[pdf (pdffs)]

Sorry for the message flood, scratch my last - having the i18n files allows the language list to be populated, but segfault still evident. Cancel language selection is the current workaround.

[B.B. Lauret (bblauret)]

I can confirm that choosing cancel is a working workaround (altough with the setup in English).

[pdf (pdffs)]

mythtv-setup will still segfault pretty frequently (quickly scrolling lists for example seems to trigger it). Can provide additional backtraces if useful.

[Fabián Rodríguez (magicfab)]

I no longer use or have access to the initial setup I had when I reported this, so I can't provide further feedback.. I am removing myself from this bug's notifications.