upgrade from 0.25 to 0.27 failed

[john pleasa]

used 'agp-get dist-upgrade' to upgrade mythbuntu 12.04 from mythtv .25 to .27
upgrade failed with "error, no database selected" error.

ProblemType: Crash
DistroRelease: Ubuntu 12.04
Package: mythtv-common 2:0.27.0+fixes.20130906.e8093db-0ubuntu0mythbuntu2 [origin: LP-PPA-mythbuntu-0.27]
ProcVersionSignature: Ubuntu 3.2.0-30.48-generic 3.2.27
Uname: Linux 3.2.0-30-generic x86_64
NonfreeKernelModules: nvidia
.var.log.mythtv.mythavtest.log:

.var.log.mythtv.mythccextractor.log:

.var.log.mythtv.mythjobqueue.log:

.var.log.mythtv.mythlcdserver.log:

.var.log.mythtv.mythmediaserver.log:

.var.log.mythtv.mythshutdown.log:

.var.log.mythtv.mythtranscode.log:

.var.log.mythtv.mythutil.log:

.var.log.mythtv.mythwelcome.log:

ApportVersion: 2.0.1-0ubuntu13
Architecture: amd64
CrashDB: mythbuntu
Date: Fri Sep 6 07:52:39 2013
Disassembly: => 0x0: Cannot access memory at address 0x0
ExecutablePath: /usr/bin/mythlogserver
InstallationMedia: Mythbuntu 12.04.1 "Precise Pangolin" - Release amd64 (20120818.1)
Installed_mythtv_dbg: 2:0.27.0+fixes.20130906.e8093db-0ubuntu0mythbuntu2
ProcCmdline: /usr/bin/mythlogserver --daemon --verbose general --loglevel info --quiet --syslog local7
ProcEnviron:
 TERM=linux
 PATH=(custom, no user)
 LANG=en_US.UTF-8
SegvAnalysis:
 Segfault happened at: 0x0: Cannot access memory at address 0x0
 PC (0x00000000) not located in a known VMA region (needed executable region)!
 Stack memory exhausted (SP below stack segment)
SegvReason: executing NULL VMA
Signal: 11
SourcePackage: mythtv
StacktraceTop:
 ?? ()
 QObject::disconnect(QObject const*, char const*, QObject const*, char const*) () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4
 QObject::disconnect (this=0x7f0f2c00b6c0, receiver=0x7f0f2400b360, member=0x0) at /usr/include/qt4/QtCore/qobject.h:252
 nzmqt::PollingZMQContext::unregisterSocket (this=0x7f0f2400b360, socket_=0x7f0f2c00b6c0) at ../include/nzmqt/nzmqt.hpp:703
 nzmqt::PollingZMQContext::qt_static_metacall (_o=0x7f0f2400b360, _c=QMetaObject::InvokeMetaMethod, _id=3, _a=0x1481ac0) at moc_nzmqt.cpp:401
Title: mythlogserver crashed with SIGSEGV in QObject::disconnect()
UpgradeStatus: No upgrade log present (probably fresh install)
UserGroups: audio cdrom dialout video

[Thomas Mashos (tgm4883)]

Your /etc/mythtv/config.xml is incorrect. Please verify that the credentials and host in /etc/mythtv/config.xml matches that in /etc/mythtv/mysql.txt (to be clear, /etc/mythtv/mysql.txt is probably correct, and you need to fix /etc/mythtv/config.xml)

[john pleasa (jzigpublic)]

Looking back at the original drive before trying to upgrade, it turns out that the file /etc/mythtv/config.xml existed but was a file of zero length, causing the upgrade to produce a non-working /etc/mythtv/config.xml. Then when the upgrade gets to installing the 0.27 mythtvbackend package it fails with a "no database selected" error and halts the upgrade at that point leaving things in a non working state.

I have no idea why /etc/mythtv/config.xml was zero length. There is a valid config.xml at /home/ziggy/.mythtv/config.xml. Copying this file to /etc/mythtv/config.xml before trying to upgrade to 0.27 allows an upgrade to go to completion.

I have tried clean installs from the same media used originally and they produce /etc/mythtv/config.xml with proper settings. Some upgrade or configuration over the past year must have caused that file to be recreated with no contents.?.

Perhaps doing a sanity check on /etc/mythtv/config.xml before starting a 0.27 upgrade would be a good idea to prevent an upgrade failure.

[tim davis (l0unchpad)]

I had exactly the same problem and also found /etc/mythtv/config.xml was zero length, but the error persisted after correcting the file.

Turned out that I didn't have xpath installed (libxml-xpath-perl) and the mythtv-database package's postinit script suppresses errors from xpath.

libxml-xpath-perl is a dependency of mythtv-common, but not mythtv-database. I'm wondering now if it's simply because I tried using apt-get upgrade initially instead of dist-upgrade.