I'll paste the stack trace in line, as I'm not sure how stable pastebin is: (gdb) bt #0 0xb7f7e424 in __kernel_vsyscall () #1 0xb7687763 in __open_nocancel () from /lib/tls/i686/cmov/libc.so.6 #2 0xb76205cd in _IO_new_file_fopen (fp=0x86e9f90, filename=0xb7a94112 "/proc/mounts", mode=0xbff9b270 "rc", is32not64=1) at fileops.c:228 #3 0xb7613a3d in __fopen_internal (filename=0xb7a94112 "/proc/mounts", mode=0xbff9b270 "rc", is32=1) at iofopen.c:93 #4 0xb7613a9c in _IO_new_fopen (filename=0xb7a94112 "/proc/mounts", mode=0xbff9b270 "rc") at iofopen.c:107 #5 0xb7691ef8 in __setmntent (file=0xb7a94112 "/proc/mounts", mode=0xb7a92e73 "r") at mntent_r.c:47 #6 0xb7a7320a in _g_get_unix_mounts () at /build/buildd/glib2.0-2.20.1/gio/gunixmounts.c:364 #7 0xb7a735fd in IA__g_unix_mounts_get (time_read=0x0) at /build/buildd/glib2.0-2.20.1/gio/gunixmounts.c:1101 #8 0xb7a7363f in IA__g_unix_mount_at (mount_path=0x86a30e8 "/usr/share/fonts/truetype/dustin", time_read=0x0) at /build/buildd/glib2.0-2.20.1/gio/gunixmounts.c:1122 #9 0xb7a76c00 in mounts_changed (mount_monitor=0x8691150, user_data=0x869e2d8) at /build/buildd/glib2.0-2.20.1/gio/glocaldirectorymonitor.c:186 #10 0xb78013a4 in IA__g_cclosure_marshal_VOID__VOID (closure=0x86a32d8, return_value=0x0, n_param_values=1, param_values=0x86ada00, invocation_hint=0xbff9b9dc, marshal_data=0xb7a76bd0) at /build/buildd/glib2.0-2.20.1/gobject/gmarshal.c:77 #11 0xb77f3c7b in IA__g_closure_invoke (closure=0x86a32d8, return_value=0x0, n_param_values=1, param_values=0x86ada00, invocation_hint=0xbff9b9dc) at /build/buildd/glib2.0-2.20.1/gobject/gclosure.c:767 #12 0xb7809e57 in signal_emit_unlocked_R (node=0x869b038, detail=0, instance=0x8691150, emission_return=0x0, instance_and_params=0x86ada00) at /build/buildd/glib2.0-2.20.1/gobject/gsignal.c:3247 #13 0xb780b4b9 in IA__g_signal_emit_valist (instance=0x8691150, signal_id=43, detail=0, var_args=0xbff9bb7c "�_\202��\217��\217��:\023��\025V\b�Sm\b") at /build/buildd/glib2.0-2.20.1/gobject/gsignal.c:2980 #14 0xb780b936 in IA__g_signal_emit (instance=0x8691150, signal_id=43, detail=0) at /build/buildd/glib2.0-2.20.1/gobject/gsignal.c:3037 #15 0xb7a7294d in mtab_file_changed (monitor=0x85615d8, file=0x86d53a0, other_file=0x0, event_type=G_FILE_MONITOR_EVENT_CHANGED, user_data=0x8691150) ---Type to continue, or q to quit--- at /build/buildd/glib2.0-2.20.1/gio/gunixmounts.c:1283 #16 0xb7a8133a in _gio_marshal_VOID__OBJECT_OBJECT_ENUM (closure=0x869b6d0, return_value=0x0, n_param_values=4, param_values=0x86b0f80, invocation_hint=0xbff9bd1c, marshal_data=0xb7a72900) at /build/buildd/glib2.0-2.20.1/gio/gio-marshal.c:198 #17 0xb77f3c7b in IA__g_closure_invoke (closure=0x869b6d0, return_value=0x0, n_param_values=4, param_values=0x86b0f80, invocation_hint=0xbff9bd1c) at /build/buildd/glib2.0-2.20.1/gobject/gclosure.c:767 #18 0xb7809e57 in signal_emit_unlocked_R (node=0x85a9ef8, detail=0, instance=0x85615d8, emission_return=0x0, instance_and_params=0x86b0f80) at /build/buildd/glib2.0-2.20.1/gobject/gsignal.c:3247 #19 0xb780b4b9 in IA__g_signal_emit_valist (instance=0x85615d8, signal_id=42, detail=0, var_args=0xbff9bec8 "P\to\b�o~�<��\210\234n\b��\201|v��\025V\b��u\031") at /build/buildd/glib2.0-2.20.1/gobject/gsignal.c:2980 #20 0xb780b936 in IA__g_signal_emit (instance=0x85615d8, signal_id=42, detail=0) at /build/buildd/glib2.0-2.20.1/gobject/gsignal.c:3037 #21 0xb7a58b9b in emit_cb (data=0x85615d8) at /build/buildd/glib2.0-2.20.1/gio/gfilemonitor.c:370 #22 0xb7767c81 in g_idle_dispatch (source=0x86e9c88, callback=0x14, user_data=0x85615d8) at /build/buildd/glib2.0-2.20.1/glib/gmain.c:3922 #23 0xb7769b88 in IA__g_main_context_dispatch (context=0x85636e0) at /build/buildd/glib2.0-2.20.1/glib/gmain.c:1814 #24 0xb776d0eb in g_main_context_iterate (context=0x85636e0, block=1, dispatch=1, self=0x853b3e8) at /build/buildd/glib2.0-2.20.1/glib/gmain.c:2448 #25 0xb776d5ba in IA__g_main_loop_run (loop=0x8691ca8) at /build/buildd/glib2.0-2.20.1/glib/gmain.c:2656 #26 0xb7ce97d9 in gtk_main () from /usr/lib/libgtk-x11-2.0.so.0 #27 0x0804ba2d in main ()