unmounting crashes pcmanfm

Thank you very much for the report.
In regards of "exited normally" message I would like to ask you if there were another pcmanfm process running (so your run only bounced action to it) or it was single process?

There were no other pcmanfm processes active, it was a single process.

I.e. it was a single process when you ran it under gdb and it wasn't returned immediately after you entered 'run'? If it did then you have to kill all existing pcmanfm processes first. And since I never able to reproduce that weird thing, I need your help. If you wish to help then run pcmanfm built from latest GIT sources with debug enabled (see instructions at http://wiki.lxde.org/en/LXDE:PCManFM_build_and_setup_guide please) and let me see all the debug messages from it when you next time happen to meet the bug. Thank you in advance.

It was running as a single process. However, when you are saying "you have to
kill all existing pcmanfm processes", do you also mean the process used for handling the desktop (pcmanfm --desktop --profile LXDE)?

Sure enough I compiled the latest sources and installed the debuginfo rpm's for libfm and pcmanfm and have not been able to reproduce as of yet. Will keep trying though ...

Yes, exactly, I meant to kill every running pcmanfm before starting it under gdb - that includes desktop managing one. Because pcmanfm works such way - if you start another instance when one was running, the new instance will communicate with the first one and send it the entered data then exit, so first running will really execute that but new instance will just exit without opening even a single window.
I hope you can catch the bug again so we finally can find what was bugged. Thank you very much.

Right, managed to crash it by unmounting an USB drive and a NFS share consecutively (all from separate tabs on the same pcmanfm instance). There still was a tab open to a folder on the localhost.

Here is the gdb trace:

(gdb) run
Starting program: /usr/bin/pcmanfm
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib64/libthread_db.so.1".
[New Thread 0x7ffff12d7700 (LWP 4072)]
[New Thread 0x7ffff08a4700 (LWP 4073)]
warning: cannot close "/usr/lib64/gio/modules/libgiofam.so": Invalid operation
warning: cannot close "/lib64/libfam.so.0": Invalid operation
[New Thread 0x7fffdf19a700 (LWP 4075)]
[New Thread 0x7fffde999700 (LWP 4076)]
[Thread 0x7fffdf19a700 (LWP 4075) exited]
[Thread 0x7fffde999700 (LWP 4076) exited]
[Thread 0x7ffff08a4700 (LWP 4073) exited]
[New Thread 0x7ffff08a4700 (LWP 4136)]
[New Thread 0x7fffde999700 (LWP 4137)]
[Thread 0x7fffde999700 (LWP 4137) exited]
[New Thread 0x7fffde999700 (LWP 4138)]
[New Thread 0x7fffdf19a700 (LWP 4139)]
[Thread 0x7fffdf19a700 (LWP 4139) exited]
[Thread 0x7fffde999700 (LWP 4138) exited]
[New Thread 0x7fffde999700 (LWP 4150)]
[Thread 0x7fffde999700 (LWP 4150) exited]
[New Thread 0x7fffde999700 (LWP 4152)]
[Thread 0x7fffde999700 (LWP 4152) exited]
[New Thread 0x7fffde999700 (LWP 4153)]
[New Thread 0x7fffdf19a700 (LWP 4154)]
[Thread 0x7fffdf19a700 (LWP 4154) exited]
[New Thread 0x7fffdf19a700 (LWP 4155)]
[Thread 0x7fffdf19a700 (LWP 4155) exited]
[Thread 0x7fffde999700 (LWP 4153) exited]
Detaching after fork from child process 4156.
[Thread 0x7ffff08a4700 (LWP 4136) exited]
[New Thread 0x7ffff08a4700 (LWP 4159)]
[New Thread 0x7fffde999700 (LWP 4160)]
[Thread 0x7fffde999700 (LWP 4160) exited]
[Thread 0x7ffff08a4700 (LWP 4159) exited]
[New Thread 0x7ffff08a4700 (LWP 4162)]
[New Thread 0x7fffde999700 (LWP 4163)]
[Thread 0x7fffde999700 (LWP 4163) exited]
[Thread 0x7ffff08a4700 (LWP 4162) exited]
[New Thread 0x7ffff08a4700 (LWP 4366)]
[New Thread 0x7fffde999700 (LWP 4367)]
[New Thread 0x7fffdf19a700 (LWP 4368)]
[New Thread 0x7fffde198700 (LWP 4369)]
[Thread 0x7fffde198700 (LWP 4369) exited]
[New Thread 0x7fffde198700 (LWP 4370)]
[Thread 0x7fffde198700 (LWP 4370) exited]
[New Thread 0x7fffde198700 (LWP 4371)]
[Thread 0x7fffde198700 (LWP 4371) exited]
[New Thread 0x7fffde198700 (LWP 4372)]
[Thread 0x7fffde198700 (LWP 4372) exited]
[Thread 0x7fffdf19a700 (LWP 4368) exited]
[Thread 0x7fffde999700 (LWP 4367) exited]
[New Thread 0x7fffde999700 (LWP 4374)]
[Thread 0x7fffde999700 (LWP 4374) exited]
[New Thread 0x7fffde999700 (LWP 4375)]
[Thread 0x7fffde999700 (LWP 4375) exited]

(pcmanfm:4068): GLib-GObject-WARNING **: instance of invalid non-instantiatable type `<invalid>'

(pcmanfm:4068): GLib-GObject-CRITICAL **: g_signal_handlers_disconnect_matched: assertion `G_TYPE_CHECK_INSTANCE (instance)' failed

(pcmanfm:4068): GLib-GObject-CRITICAL **: g_object_steal_data: assertion `G_IS_OBJECT (object)' failed

(pcmanfm:4068): GLib-GObject-CRITICAL **: g_object_set_data: assertion `G_IS_OBJECT (object)' failed

(pcmanfm:4068): GLib-GObject-WARNING **: instance with invalid (NULL) class pointer

(pcmanfm:4068): GLib-GObject-CRITICAL **: g_signal_handlers_disconnect_matched: assertion `G_TYPE_CHECK_INSTANCE (instance)' failed

(pcmanfm:4068): GLib-GObject-CRITICAL **: g_object_steal_data: assertion `G_IS_OBJECT (object)' failed

(pcmanfm:4068): GLib-GObject-CRITICAL **: g_object_set_data: assertion `G_IS_OBJECT (object)' failed
[Thread 0x7ffff08a4700 (LWP 4366) exited]
[Thread 0x7ffff12d7700 (LWP 4072) exited]
[Inferior 1 (process 4068) exited normally]

Thank you very much. At least now it is clear it isn't a crash but something else is weird. But unfortunately it still gives no clue what happened, because you've missed one thing which I would be very glad if you did - you don't enabled debug messages and errors catch. That might be done by setting few environment variables as that was mentioned at said wiki page in the chapter about debugging. Read that page thoroughly please. I would be very grateful if you could do that and try to catch the issue again. That will give a lot more information. Thanks in advance.

When setting the environment variables for debugging, pcmanfm is no longer able to mount/use the NFS share. The gdb session shows:

** (pcmanfm:9818): DEBUG: line = /data/mcxfrwi
** (pcmanfm:9818): DEBUG: line = 0
** (pcmanfm:9818): DEBUG: line = /data/mcxfrwi/.
** (pcmanfm:9818): DEBUG: file: /data/mcxfrwi/.
[New Thread 0x7fffdf19a700 (LWP 9842)]
** (pcmanfm:9818): DEBUG: reactivated gestures to page 1
[Thread 0x7fffdf19a700 (LWP 9842) exited]
** (pcmanfm:9818): DEBUG: error creating file monitor: The specified location is not mounted
** (pcmanfm:9818): DEBUG: file monitor cannot be created: The specified location is not mounted
[New Thread 0x7fffdf19a700 (LWP 9843)]
[New Thread 0x7ffff08a4700 (LWP 9844)]
** (pcmanfm:9818): DEBUG: FmJob error: The specified location is not mounted
[Thread 0x7ffff08a4700 (LWP 9844) exited]
[Thread 0x7fffde999700 (LWP 9834) exited]
[New Thread 0x7fffde999700 (LWP 9856)]
[New Thread 0x7ffff08a4700 (LWP 9857)]

(pcmanfm:9818): GLib-CRITICAL **: g_main_context_push_thread_default: assertion `acquired_context' failed

Program received signal SIGTRAP, Trace/breakpoint trap.
0x0000003c4004ec67 in g_logv () from /lib64/libglib-2.0.so.0

Backtracing this:

(gdb) bt
#0 0x0000003c4004ec67 in g_logv () from /lib64/libglib-2.0.so.0
#1 0x0000003c4004ee32 in g_log () from /lib64/libglib-2.0.so.0
#2 0x00007ffff08bf667 in register_vfs_filter_cb () from /usr/lib64/gio/modules/libgvfsdbus.so
#3 0x00007ffff08c0dec in register_skeleton () from /usr/lib64/gio/modules/libgvfsdbus.so
#4 0x0000003c40038330 in g_hash_table_foreach () from /lib64/libglib-2.0.so.0
#5 0x00007ffff08c0f6b in _g_dbus_connect_vfs_filters () from /usr/lib64/gio/modules/libgvfsdbus.so
#6 0x00007ffff08b7081 in async_proxy_new_cb () from /usr/lib64/gio/modules/libgvfsdbus.so
#7 0x0000003c4206dff7 in g_simple_async_result_complete () from /lib64/libgio-2.0.so.0
#8 0x0000003c4206e0f9 in complete_in_idle_cb () from /lib64/libgio-2.0.so.0
#9 0x0000003c40047a55 in g_main_context_dispatch () from /lib64/libglib-2.0.so.0
#10 0x0000003c40047d88 in g_main_context_iterate.isra.24 () from /lib64/libglib-2.0.so.0
#11 0x0000003c40048182 in g_main_loop_run () from /lib64/libglib-2.0.so.0
#12 0x0000003c57d8dd4d in gtk_main () from /lib64/libgtk-3.so.0
#13 0x000000000040d836 in main (argc=1, argv=0x7fffffffde08) at pcmanfm.c:234

It points to glib2 (glib2-2.34.2-2) so it seems. I'll see if I can upgrade to Fedora19 (has newer glib2-2.36.3-2) and reproduce. May not happen overnight though ....

Your gdb output shows a problem in GVFS. Not in glib though, see frame #2. Unfortunately you cannot get to next error to examine it until this one is fixed. I hope you can fix that problem in GVFS so you can explore the issue more. Thank you very much.

Have you got any new data?

Afraid not at the moment. I have upgraded GVFS to 1.17 but that did not really help. Problem is that holidays are still going on over here, with many colleagues gone it is hard to find the time do really do some debugging.

I am using Nautilus as a workaround now when using NFS mounts.

BTW, I have updated libfm to 1.2.0 alpha 5 en pcmanfm to 1.1.2 (git state of 13 Aug).

This one is still on my mind, so no worries that I will forget ...

Thank you a lot!

And you know, it may be that I've fixed it somehow along with latest fixes in pcmanfm so it may happen you cannot catch this bug anymore. In any case I will be glad to hear any news.

bug is still present, I can tell you that much. Thing is that when I enable debugging and use gdb, I cannot even use the mountpoints (sftp), simply browsing will make it crash. Anyways, when I have more time I will try to ge some proper debug info.

Just a thought, will Nautilus use the GVFS part as well? Cause Nautilus does not seem to experience these problems. I just don't like Nautilus ;-)

I don't like it either. :) Nautilus uses GFVS as well, you probaly just don't run it with environment to crash on criticals. That is sad it is still around. May be I should try to setup fedora in virtual box to experiment with it...

I've installed fc19 into virtual box and I still could not reproduce your issue even with fedora default pcmanfm. I know, virtual box isn't the same as real one. BTW, let me ask you, do you compile it by default, with gtk2, or by fedora way, with gtk3? Gtk3 is buggy so if you use gtk3 version I would suggest you try gtk2 instead.

Compiled libfm and pcmanfm using gtk2, same result. It crashes consistently when using sftp connections.

My exact steps:
- open pcmanfm (only instance, desktop is not handled by pcmanfm)
- open a sftp connection
- open a file on the sftp connection with geany
- open a new tab in pcfmanfm with arbitrary local folder (Documents for example)
- try to unmount sftp connection in pcmanfm
=> crash

Weird that you can not reproduce. I tried the above in VirtualBox as well.

That is weird because I still cannot reproduce it, even using your extended recipe with geany. I don't know what to do with it. I would like to get your help. I want you to set environment G_MESSAGES_DEBUG=all (don't set criticals to fail as you did earlier since it fails in gvfs) and start pcmanfm. After it closes all tabs instead of one (i.e. bug happens), collect all the debug and let me see it, please, I'll try to find out what to do with it next. Thank you in advance.

Thanks for all the effort you put into this, I really appreciate it!

OK, here we go. This appears in the gdb session when I select to unmount the sftp connection (SPECS was the folder opened on the sftp connection):
** (pcmanfm:1784): DEBUG: reactivated gestures to page 0
** (pcmanfm:1784): DEBUG: reactivated gestures to page 0
** (pcmanfm:1784): DEBUG: FmMainWin: removed page 0; 1 pages left
** (pcmanfm:1784): DEBUG: fm_tab_page_destroy, folder: SPECS
** (pcmanfm:1784): DEBUG: fm_tab_page_destroy, folder: (none)

Program received signal SIGSEGV, Segmentation fault.
g_type_check_instance (type_instance=type_instance@entry=0x9b4470) at gtype.c:4082
4082 TypeNode *node = lookup_type_node_I (type_instance->g_class->g_type);

Here is the bt:
(gdb) bt
#0 g_type_check_instance (type_instance=type_instance@entry=0x9b4470) at gtype.c:4082
#1 0x00007ffff739dc64 in g_signal_handlers_disconnect_matched (instance=0x9b4470,
mask=mask@entry=(G_SIGNAL_MATCH_FUNC | G_SIGNAL_MATCH_DATA), signal_id=signal_id@entry=0, detail=detail@entry=0,
closure=closure@entry=0x0, func=func@entry=0x32bc199b40 <attach_widget_screen_changed>, data=data@entry=0x9a6ff0)
at gsignal.c:2874
#2 0x00000032bc19cf2b in gtk_menu_detach (menu=0x9a6ff0) at gtkmenu.c:1297
#3 0x00000032bc19d057 in gtk_menu_destroy (widget=0x9a6ff0) at gtkmenu.c:1111
#4 0x00007ffff7384e38 in g_closure_invoke (closure=closure@entry=0x62b6d0, return_value=return_value@entry=0x0, n_param_values=1,
param_values=param_values@entry=0x7fffffffd1b0, invocation_hint=invocation_hint@entry=0x7fffffffd150) at gclosure.c:777
#5 0x00007ffff7397674 in signal_emit_unlocked_R (node=node@entry=0x62b740, detail=detail@entry=0,
instance=instance@entry=0x9a6ff0, emission_return=emission_return@entry=0x0,
instance_and_params=instance_and_params@entry=0x7fffffffd1b0) at gsignal.c:3698
#6 0x00007ffff739f4f2 in g_signal_emit_valist (instance=<optimized out>, signal_id=<optimized out>, detail=<optimized out>,
var_args=var_args@entry=0x7fffffffd338) at gsignal.c:3326
#7 0x00007ffff739f7c2 in g_signal_emit (instance=instance@entry=0x9a6ff0, signal_id=<optimized out>, detail=detail@entry=0)
at gsignal.c:3382
#8 0x00000032bc2b6cb0 in gtk_widget_dispose (object=0x9a6ff0) at gtkwidget.c:10771
#9 0x00007ffff738b7d1 in g_object_run_dispose (object=0x9a6ff0) at gobject.c:1067
#10 0x00007ffff7385067 in _g_closure_invoke_va (closure=closure@entry=0xb23310, return_value=return_value@entry=0x0,
instance=instance@entry=0x9a6ff0, args=args@entry=0x7fffffffd618, n_params=0, param_types=0x0) at gclosure.c:840
#11 0x00007ffff739eeb6 in g_signal_emit_valist (instance=<optimized out>, signal_id=<optimized out>, detail=0,
var_args=var_args@entry=0x7fffffffd618) at gsignal.c:3234
#12 0x00007ffff739f7c2 in g_signal_emit (instance=<optimized out>, signal_id=<optimized out>, detail=detail@entry=0)
at gsignal.c:3382
#13 0x00000032bc1a5d62 in gtk_menu_shell_activate_item (menu_shell=0x9a6ff0, menu_item=0x7eccb0, force_deactivate=<optimized out>)
at gtkmenushell.c:1433
#14 0x00000032bc1a606b in gtk_menu_shell_button_release (widget=0x9a6ff0, event=<optimized out>) at gtkmenushell.c:830
#15 0x00000032bc18b18e in _gtk_marshal_BOOLEAN__BOXEDv (closure=0x63f700, return_value=0x7fffffffd8b0, instance=<optimized out>,
args=<optimized out>, marshal_data=<optimized out>, n_params=<optimized out>, param_types=0x63f730) at gtkmarshalers.c:130
#16 0x00007ffff7385067 in _g_closure_invoke_va (closure=closure@entry=0x63f700, return_value=return_value@entry=0x7fffffffd8b0,
---Type <return> to continue, or q <return> to quit---
instance=instance@entry=0x9a6ff0, args=args@entry=0x7fffffffd9b8, n_params=1, param_types=0x63f730) at gclosure.c:840
#17 0x00007ffff739eeb6 in g_signal_emit_valist (instance=<optimized out>, signal_id=<optimized out>, detail=0,
var_args=var_args@entry=0x7fffffffd9b8) at gsignal.c:3234
#18 0x00007ffff739f7c2 in g_signal_emit (instance=instance@entry=0x9a6ff0, signal_id=<optimized out>, detail=detail@entry=0)
at gsignal.c:3382
#19 0x00000032bc2ab5c4 in gtk_widget_event_internal (widget=widget@entry=0x9a6ff0, event=event@entry=0x7f03f0) at gtkwidget.c:6714
#20 0x00000032bc2ab899 in gtk_widget_event (widget=widget@entry=0x9a6ff0, event=event@entry=0x7f03f0) at gtkwidget.c:6371
#21 0x00000032bc1894dc in propagate_event_up (topmost=<optimized out>, event=<optimized out>, widget=0x9a6ff0) at gtkmain.c:2393
#22 propagate_event (widget=<optimized out>, event=0x7f03f0, captured=<optimized out>, topmost=0x0) at gtkmain.c:2501
#23 0x00000032bc18ad75 in gtk_main_do_event (event=0x7f03f0) at gtkmain.c:1716
#24 0x00000032bc84e842 in gdk_event_source_dispatch (source=source@entry=0x67fa60, callback=<optimized out>,
user_data=<optimized out>) at gdkeventsource.c:364
#25 0x00007ffff708f0b6 in g_main_dispatch (context=0x65cef0) at gmain.c:3065
#26 g_main_context_dispatch (context=context@entry=0x65cef0) at gmain.c:3641
#27 0x00007ffff708f408 in g_main_context_iterate (context=0x65cef0, block=block@entry=1, dispatch=dispatch@entry=1,
self=<optimized out>) at gmain.c:3712
#28 0x00007ffff708f80a in g_main_loop_run (loop=0x703bc0) at gmain.c:3906
#29 0x00000032bc18a27d in gtk_main () at gtkmain.c:1156
#30 0x000000000040d840 in main (argc=1, argv=0x7fffffffdde8) at pcmanfm.c:236
(gdb)

I hope this helps.

Thank you very much for your help. I've found one suspicious place in pcmanfm. Try updated git sources, please, and tell me if the issue is fixed (hopefully!) now.

I updated to the latest git sources:

** (pcmanfm:1787): DEBUG: reactivated gestures to page 0
** (pcmanfm:1787): DEBUG: reactivated gestures to page 0
** (pcmanfm:1787): DEBUG: FmMainWin: removed page 0; 1 pages left
** (pcmanfm:1787): DEBUG: fm_tab_page_destroy, folder: SPECS
** (pcmanfm:1787): DEBUG: fm_tab_page_destroy, folder: (none)

Program received signal SIGSEGV, Segmentation fault.
g_type_check_instance (type_instance=type_instance@entry=0x9a6470) at gtype.c:4082
4082 TypeNode *node = lookup_type_node_I (type_instance->g_class->g_type);
Missing separate debuginfos, use: debuginfo-install gvfs-1.17.3-1.fc19.x86_64
(gdb) bt
#0 g_type_check_instance (type_instance=type_instance@entry=0x9a6470) at gtype.c:4082
#1 0x00007ffff6e9fc64 in g_signal_handlers_disconnect_matched (instance=0x9a6470,
mask=mask@entry=(G_SIGNAL_MATCH_FUNC | G_SIGNAL_MATCH_DATA), signal_id=signal_id@entry=0, detail=detail@entry=0,
closure=closure@entry=0x0, func=func@entry=0x32bc199b40 <attach_widget_screen_changed>, data=data@entry=0x9bcff0)
at gsignal.c:2874
#2 0x00000032bc19cf2b in gtk_menu_detach (menu=0x9bcff0) at gtkmenu.c:1297
#3 0x00000032bc19d057 in gtk_menu_destroy (widget=0x9bcff0) at gtkmenu.c:1111
#4 0x00007ffff6e86e38 in g_closure_invoke (closure=closure@entry=0x62b6d0, return_value=return_value@entry=0x0, n_param_values=1,
param_values=param_values@entry=0x7fffffffd1b0, invocation_hint=invocation_hint@entry=0x7fffffffd150) at gclosure.c:777
#5 0x00007ffff6e99674 in signal_emit_unlocked_R (node=node@entry=0x62b740, detail=detail@entry=0,
instance=instance@entry=0x9bcff0, emission_return=emission_return@entry=0x0,
instance_and_params=instance_and_params@entry=0x7fffffffd1b0) at gsignal.c:3698
#6 0x00007ffff6ea14f2 in g_signal_emit_valist (instance=<optimized out>, signal_id=<optimized out>, detail=<optimized out>,
var_args=var_args@entry=0x7fffffffd338) at gsignal.c:3326
#7 0x00007ffff6ea17c2 in g_signal_emit (instance=instance@entry=0x9bcff0, signal_id=<optimized out>, detail=detail@entry=0)
at gsignal.c:3382
#8 0x00000032bc2b6cb0 in gtk_widget_dispose (object=0x9bcff0) at gtkwidget.c:10771
#9 0x00007ffff6e8d7d1 in g_object_run_dispose (object=0x9bcff0) at gobject.c:1067
#10 0x00007ffff6e87067 in _g_closure_invoke_va (closure=closure@entry=0xb3ffb0, return_value=return_value@entry=0x0,
instance=instance@entry=0x9bcff0, args=args@entry=0x7fffffffd618, n_params=0, param_types=0x0) at gclosure.c:840
#11 0x00007ffff6ea0eb6 in g_signal_emit_valist (instance=<optimized out>, signal_id=<optimized out>, detail=0,
var_args=var_args@entry=0x7fffffffd618) at gsignal.c:3234
#12 0x00007ffff6ea17c2 in g_signal_emit (instance=<optimized out>, signal_id=<optimized out>, detail=detail@entry=0)
at gsignal.c:3382
#13 0x00000032bc1a5d62 in gtk_menu_shell_activate_item (menu_shell=0x9bcff0, menu_item=0xb03cb0, force_deactivate=<optimized out>)
at gtkmenushell.c:1433
#14 0x00000032bc1a606b in gtk_menu_shell_button_release (widget=0x9bcff0, event=<optimized out>) at gtkmenushell.c:830
#15 0x00000032bc18b18e in _gtk_marshal_BOOLEAN__BOXEDv (closure=0x63f700, return_value=0x7fffffffd8b0, instance=<optimized out>,
args=<optimized out>, marshal_data=<optimized out>, n_params=<optimized out>, param_types=0x63f730) at gtkmarshalers.c:130
#16 0x00007ffff6e87067 in _g_closure_invoke_va (closure=closure@entry=0x63f700, return_value=return_value@entry=0x7fffffffd8b0,
---Type <return> to continue, or q <return> to quit---
instance=instance@entry=0x9bcff0, args=args@entry=0x7fffffffd9b8, n_params=1, param_types=0x63f730) at gclosure.c:840
#17 0x00007ffff6ea0eb6 in g_signal_emit_valist (instance=<optimized out>, signal_id=<optimized out>, detail=0,
var_args=var_args@entry=0x7fffffffd9b8) at gsignal.c:3234
#18 0x00007ffff6ea17c2 in g_signal_emit (instance=instance@entry=0x9bcff0, signal_id=<optimized out>, detail=detail@entry=0)
at gsignal.c:3382
#19 0x00000032bc2ab5c4 in gtk_widget_event_internal (widget=widget@entry=0x9bcff0, event=event@entry=0x7fffe001ac50)
at gtkwidget.c:6714
#20 0x00000032bc2ab899 in gtk_widget_event (widget=widget@entry=0x9bcff0, event=event@entry=0x7fffe001ac50) at gtkwidget.c:6371
#21 0x00000032bc1894dc in propagate_event_up (topmost=<optimized out>, event=<optimized out>, widget=0x9bcff0) at gtkmain.c:2393
#22 propagate_event (widget=<optimized out>, event=0x7fffe001ac50, captured=<optimized out>, topmost=0x0) at gtkmain.c:2501
#23 0x00000032bc18ad75 in gtk_main_do_event (event=0x7fffe001ac50) at gtkmain.c:1716
#24 0x00000032bc84e842 in gdk_event_source_dispatch (source=source@entry=0x67fa60, callback=<optimized out>,
user_data=<optimized out>) at gdkeventsource.c:364
#25 0x00007ffff6b910b6 in g_main_dispatch (context=0x65cef0) at gmain.c:3065
#26 g_main_context_dispatch (context=context@entry=0x65cef0) at gmain.c:3641
#27 0x00007ffff6b91408 in g_main_context_iterate (context=0x65cef0, block=block@entry=1, dispatch=dispatch@entry=1,
self=<optimized out>) at gmain.c:3712
#28 0x00007ffff6b9180a in g_main_loop_run (loop=0x75f6c0) at gmain.c:3906
#29 0x00000032bc18a27d in gtk_main () at gtkmain.c:1156
#30 0x000000000040d8a0 in main (argc=1, argv=0x7fffffffdde8) at pcmanfm.c:236

There is noticable change however, the pcmanfm instance keeps running, though not usable. Only when I hit q in gdb the instance is killed after confirmation.

This is not good at all. It fails inside of gtk and I see on actual reason why it should. I would like to know exact versions of libglib and libgtk which your pcmanfm was running with so I'll try to explore it further. Thank you in advance.

I meant "no" not "on", mistyped it.