modem-manager crashed with SIGSEGV in g_slice_alloc() - Cannot connect via mobile broadband

This is the same as bug 1164023. This bug report is only to collect more crash data with Apport.

In comment #39 of bug 1164023 to collect a crash report with syslog in debug mode around the crash time.

So I ran the commands

wget http://cgit.freedesktop.org/NetworkManager/NetworkManager/plain/test/debug-helper.py
sudo python debug-helper.py --nm debug
sudo python debug-helper.py --mm debug

and after that I have (as for the original bug report) first clicked "Enable Mobile Broadband" in the Network Manager menu, near the bottom. After some seconds I got an OSD pop-up that I am registered for GSM or so. Now I clicked on "T-Mobile (Telekom) Default" in the "Mobile Broadband" section. The indicator applet icon of the Network Manager started spinning, telling that it is searched for a network. After some time the icon returned to its initial state of Ethernet connection. I did neither get another OSD message nor a connection to mobile broadband.

Much later I got the Apport pop-up.

syslog is attached.

ProblemType: Crash
DistroRelease: Ubuntu 13.04
Package: modemmanager 0.6.0.0.really-0ubuntu4
ProcVersionSignature: Ubuntu 3.8.0-17.27-generic 3.8.6
Uname: Linux 3.8.0-17-generic x86_64
ApportVersion: 2.9.2-0ubuntu5
Architecture: amd64
CrashCounter: 1
Date: Wed Apr 10 12:42:49 2013
ExecutablePath: /usr/sbin/modem-manager
InstallationDate: Installed on 2013-03-28 (12 days ago)
InstallationMedia: Ubuntu 13.04 "Raring Ringtail" - Alpha amd64 (20130328)
MarkForUpload: True
ProcCmdline: /usr/sbin/modem-manager
ProcEnviron:
 PATH=(custom, no user)
 TERM=linux
SegvAnalysis:
 Segfault happened at: 0x7f2b2e737f7f <g_slice_alloc+223>: mov (%rbx),%rax
 PC (0x7f2b2e737f7f) ok
 source "(%rbx)" (0x100000001) not located in a known VMA region (needed readable region)!
 destination "%rax" ok
SegvReason: reading unknown VMA
Signal: 11
SourcePackage: modemmanager
StacktraceTop:
 g_slice_alloc () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
 g_slice_alloc0 () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
 mm_callback_info_new_full ()
 ?? ()
 ?? ()
Title: modem-manager crashed with SIGSEGV in g_slice_alloc()
UpgradeStatus: No upgrade log present (probably fresh install)
UserGroups: