QTreeWidget causes the app to crash after deleting the last QTreeWidgetItem

[jsulm]

@Andrea_Venturelli Please check in the Kit you're using what debugger is set there. It should be GDB from MinGW.

[Andrea_Venturelli]

yes @jsulm, is GDB as illustrated in the code snippet some messages ago

this is taken from the "Global Debugger Log" panel , after running the Debug play button
and is clearly referring to GDB

• GDB PROCESS FINISHED, status 0, exit code 1 (0x1)
• d[GDB] NOTE: ENGINE SETUP FAILED

d[GDB] UNEXPECTED GDB STDERR: error: unknown option: --tty=\\.\pipe\creator-11944-28798
derror: unknown option: -i
dUse 'lldb.exe --help' for a complete list of options.
d[GDB] GDB PROCESS FINISHED, status 0, exit code 1 (0x1)
d[GDB] NOTE: ENGINE SETUP FAILED
d[GDB] State changed from EngineSetupRequested(1) to EngineSetupFailed(2)
<Debugging has failed.
d[GDB] State changed from EngineSetupFailed(2) to DebuggerFinished(16)

[jsulm]

@Andrea_Venturelli said in QTreeWidget causes the app to crash after deleting the last QTreeWidgetItem:

dUse 'lldb.exe --help' for a complete list of options.

Why don't you simply check in the Kit which debugger is set?

[Andrea_Venturelli]

how can i do that? it's not clear to me, where the informations of the debug type resides; a screenshot could be helpfull or even the path like so:

[Qt creator] >> Edit >> Preferences... >> Debugger .. and so on or
[Qt Maintenance Tool] >> Extencion >> ecc..

because I have a little experience with Qt Creator, resulting in me, not knowing where to look for

[jsulm]

@Andrea_Venturelli [Qt creator] >> Edit >> Preferences... >> Kits - then select the Kit you're using

[Andrea_Venturelli]

this is what I use to create the projects (and using qMake to built):

[jsulm]

@Andrea_Venturelli Please show ALL settings of that Kit (especially Qt version and debugger set).

[Andrea_Venturelli]

Desktop Qt 6.7.1 llvm-mingw 64-bit

c++ compiler:

LLVM-MinGW 17.0.6 64-bit for c++

Debugger:

LLVM lldb 17.0.6 64-bit

Qt version:

Qt 6.7.1 llvm-mingw 64-bit

CMake Tool:

CMake 3.27.7 (Qt)

[jsulm]

@Andrea_Venturelli Try with Qt for MinGW (not llvm-mingw).
Maybe QtCreator does not support lldb properly.

[cristian-adam]

It looks like the LLVM MInGW debugger has the wrong debugger type set. It should be LLDB and not GDB.

https://bugreports.qt.io/browse/QTBUG-123330 was supposed to be a thing of the past...

[Andrea_Venturelli]

How should I change the current project KIT, transitioning from llvm-mingw to MinGW ??

I tryed it, from the preferences panel under: Edit >> Preferences... >> Kits
but I'm pretty sure that has no impact on the current project, instead will change the default Kit, the next time I'll create a new project.

Exists such a way to change the Kit to the current running project or I'm forced to create a brand-new one and manually paste the code?

[jsulm]

@Andrea_Venturelli said in QTreeWidget causes the app to crash after deleting the last QTreeWidgetItem:

How should I change the current project KIT, transitioning from llvm-mingw to MinGW ??

On the right side in QtCreator "Projects".
From your screen-shots it looks like you already have a Kit for Qt MinGW.

[Andrea_Venturelli]

okay, finally we did it!
for the other reader who might encounter this problem with the debugger, the solution is:

1. on the left panel (where it is "Welcome", "Edit", "Design") there is "Projects"
2. open projects and under "Built & Run" you have all the kit available
3. I switched from Desktop Qt 6.7.1 llvm-mingw 64-bit to Desktop Qt 6.7.1 MinGW 64-bit
4. I pressed the "run" button and compile fine.
5. after I Run the normal "Debug play button" at the bottom left cornern and now is working

now we can go back to the main issues where this discussion started

[Andrea_Venturelli]

this is the error I get after deleting the last item in the QTreeWidget:

here the call stack:

I also found out where was the problem, other then I'm a big chicken ;)

SOLUTION

I had the QTreeWidget::ItemChanged signal, connected to one of my custom slots where i automatically update the values inside the LineEdits. But I ignored that, even when the last item is deleted, the QTreeWidget calls the "ItemChanged" signal.

adding a check if the, before trying to retrive information from an empty QTreeWidgetItem solved the problem

void Dialog::on_treeWidgetItemChanged()
{
    // check control
    if (m_paths.count())
    {
        auto current_itm = ui->left_wdg->currentItem();

        // update the lineEdit' values
        ui->fn_le->setText(current_itm->text(0));           // THIS WAS THE CAUSE OF THE ERROR
        ui->fPath_le->setText(current_itm->text(1));
    }
}