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  4. Called object is not of the correct type (class destructor may have already run) - what is it? o.o
Forum Update on Monday, May 27th 2025

Called object is not of the correct type (class destructor may have already run) - what is it? o.o

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  • D Dariusz

    Hey
    @JonB Its definitely alive, it runs fine on windows, and when I debug it I can see item with valid data/etc. & its QComboBox
    @mrjj Sorry my bad! Its> setCurrentIndex.

    I've removed it now to "skip the crash" to test more and I crashed again on another thing totally. Mac... fun time.
    It feels like calling a slot on Qt item can cause explosion...
    Here is screnschot of comboBox trace log >
    Screenshot 2022-06-24 at 16.28.05.png

    I'm lost, trying to dig through it somehow.

    Ok I'm closer to answer...
    I cant do this >
    connect(mRange, static_cast<void (QComboBox::*)(int)>(&QComboBox::currentIndexChanged), this, &icCurveWidget::pushUpdate);
    My "new" signals breaks I have to revert back to old(sender, SIGNAL() , this,SLOT()); :- (((( no idea why the new ones wont work for me:/

    This object is made by a dylib plugin that creates view, which is a static library imported to main app that imports dylib. I wonder if I need to add some kind of... export macros hmmmmmmmmm

    M Offline
    M Offline
    mchinand
    wrote on last edited by
    #6

    Use qOverload instead of static_cast. See Selecting Overloaded Signals and Slots

    1 Reply Last reply
    4
    • D Offline
      D Offline
      Dariusz
      wrote on last edited by
      #7

      Hey

      Yeah thats a crazy one overload, looking at data years old so uhh my bad!

      Fixing it sadly did not help, another signal/slots screams here >

      This crash > connect(addItem, &QAction::triggered, this, &icCGraphicsScene::addItemPoint);
      This works > connect(addItem, &QAction::triggered, this, [this]() { this->addItemPoint(); });
      Yes I know the "works" one is not good, but I simply cant connect normal signals on M1 mac. Maybe its ARM issue ?

      JonBJ KroMignonK 2 Replies Last reply
      0
      • D Dariusz

        Hey

        Yeah thats a crazy one overload, looking at data years old so uhh my bad!

        Fixing it sadly did not help, another signal/slots screams here >

        This crash > connect(addItem, &QAction::triggered, this, &icCGraphicsScene::addItemPoint);
        This works > connect(addItem, &QAction::triggered, this, [this]() { this->addItemPoint(); });
        Yes I know the "works" one is not good, but I simply cant connect normal signals on M1 mac. Maybe its ARM issue ?

        JonBJ Offline
        JonBJ Offline
        JonB
        wrote on last edited by
        #8

        @Dariusz
        If somebody can help further they will surely want to know what version of Qt you are using and what kind of MacOS version?

        D 1 Reply Last reply
        0
        • JonBJ JonB

          @Dariusz
          If somebody can help further they will surely want to know what version of Qt you are using and what kind of MacOS version?

          D Offline
          D Offline
          Dariusz
          wrote on last edited by
          #9

          @JonB 6.3.0, MacOS Monterey 12.4 (21F79). Mac M1 Mini.
          I've had this problem for year + now I think.

          Cant signal slot 50% of my connections for some reason.

          Just did not know that this error is this. I usually fix it via either old SIGNAL(), SLOT() connection or lambda :/

          JonBJ 1 Reply Last reply
          0
          • D Dariusz

            @JonB 6.3.0, MacOS Monterey 12.4 (21F79). Mac M1 Mini.
            I've had this problem for year + now I think.

            Cant signal slot 50% of my connections for some reason.

            Just did not know that this error is this. I usually fix it via either old SIGNAL(), SLOT() connection or lambda :/

            JonBJ Offline
            JonBJ Offline
            JonB
            wrote on last edited by
            #10

            @Dariusz
            ...and then someone will ask whether you can produce any one minimal example which shows this problem for you, so they can actually try it...? :)

            D 1 Reply Last reply
            0
            • JonBJ JonB

              @Dariusz
              ...and then someone will ask whether you can produce any one minimal example which shows this problem for you, so they can actually try it...? :)

              D Offline
              D Offline
              Dariusz
              wrote on last edited by
              #11

              @JonB Its been on my todo list for a year :- )

              I will eventually make it...

              I'm sorry, its topic repeat, I know the answer is null till I post a git project that can reproduce it, its just lots of work to do it :D
              I just didn't realise it was signal error again, sigh.
              Sorri, & thank you for help <3
              Regards
              Dariusz

              1 Reply Last reply
              0
              • D Dariusz

                Hey

                Yeah thats a crazy one overload, looking at data years old so uhh my bad!

                Fixing it sadly did not help, another signal/slots screams here >

                This crash > connect(addItem, &QAction::triggered, this, &icCGraphicsScene::addItemPoint);
                This works > connect(addItem, &QAction::triggered, this, [this]() { this->addItemPoint(); });
                Yes I know the "works" one is not good, but I simply cant connect normal signals on M1 mac. Maybe its ARM issue ?

                KroMignonK Offline
                KroMignonK Offline
                KroMignon
                wrote on last edited by
                #12

                @Dariusz said in Called object is not of the correct type (class destructor may have already run) - what is it? o.o:

                Hey
                Yeah thats a crazy one overload, looking at data years old so uhh my bad!
                Fixing it sadly did not help, another signal/slots screams here >
                This crash > connect(addItem, &QAction::triggered, this, &icCGraphicsScene::addItemPoint);
                This works > connect(addItem, &QAction::triggered, this, this { this->addItemPoint(); });
                Yes I know the "works" one is not good, but I simply cant connect normal signals on M1 mac. Maybe its ARM issue ?

                DISCLAIMER: I have never developed Qt application for Mac (or used a Mac).

                My guess is that you have an issue on instance class life cycle.
                When creating a lambda function, the captured variables are copied.

                But this is just a fealling...

                It is an old maxim of mine that when you have excluded the impossible, whatever remains, however improbable, must be the truth. (Sherlock Holmes)

                D 1 Reply Last reply
                0
                • KroMignonK KroMignon

                  @Dariusz said in Called object is not of the correct type (class destructor may have already run) - what is it? o.o:

                  Hey
                  Yeah thats a crazy one overload, looking at data years old so uhh my bad!
                  Fixing it sadly did not help, another signal/slots screams here >
                  This crash > connect(addItem, &QAction::triggered, this, &icCGraphicsScene::addItemPoint);
                  This works > connect(addItem, &QAction::triggered, this, this { this->addItemPoint(); });
                  Yes I know the "works" one is not good, but I simply cant connect normal signals on M1 mac. Maybe its ARM issue ?

                  DISCLAIMER: I have never developed Qt application for Mac (or used a Mac).

                  My guess is that you have an issue on instance class life cycle.
                  When creating a lambda function, the captured variables are copied.

                  But this is just a fealling...

                  D Offline
                  D Offline
                  Dariusz
                  wrote on last edited by Dariusz
                  #13

                  @KroMignon I'm back to this hell of an issue :- D

                  Nope live-time is not the problem. Both objects are alive.

                  Seems like he can't resolve signals/names somehow properly.
                  Perhaps its my namespace.
                  Or ARM
                  Or there is some build flag I'm missing.

                  I just did big update to my UI library, everything works on Windows, but I go to MAC and he ignores all signal/slots connections, or most of them. I'm linking against static .a library creating dylib one and loading it in my app at runtime.

                  At some point Qt for mac fails in my crazy build :/

                  I have to redo all my signals now from signal>signal or signal>slot connections to signal>lambda ;/////

                  qOverload sadly does not work either.

                  QLineEdit will just crash (or my customLineEdit) and QCheckBox will just "not work".

                  im on 6.5 Qt btw. moved from 6.1 I think.

                  M 1 Reply Last reply
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                  • D Dariusz

                    @KroMignon I'm back to this hell of an issue :- D

                    Nope live-time is not the problem. Both objects are alive.

                    Seems like he can't resolve signals/names somehow properly.
                    Perhaps its my namespace.
                    Or ARM
                    Or there is some build flag I'm missing.

                    I just did big update to my UI library, everything works on Windows, but I go to MAC and he ignores all signal/slots connections, or most of them. I'm linking against static .a library creating dylib one and loading it in my app at runtime.

                    At some point Qt for mac fails in my crazy build :/

                    I have to redo all my signals now from signal>signal or signal>slot connections to signal>lambda ;/////

                    qOverload sadly does not work either.

                    QLineEdit will just crash (or my customLineEdit) and QCheckBox will just "not work".

                    im on 6.5 Qt btw. moved from 6.1 I think.

                    M Offline
                    M Offline
                    Marcus Tillmanns
                    wrote on last edited by
                    #14

                    @Dariusz
                    I'm having the same issue (also M1 mac, haven't tried on other platforms yet). The problem seems to be that inside Qt code, the call to call dynamic_cast<>() fails for my object, even though it should work. The target class that it cannot dynamic_cast to is defined in a static library. When I change it to a dynamic library instead, everything works fine.

                    Did you have any more luck in the mean time?

                    J.HilkJ SGaistS 2 Replies Last reply
                    1
                    • M Marcus Tillmanns

                      @Dariusz
                      I'm having the same issue (also M1 mac, haven't tried on other platforms yet). The problem seems to be that inside Qt code, the call to call dynamic_cast<>() fails for my object, even though it should work. The target class that it cannot dynamic_cast to is defined in a static library. When I change it to a dynamic library instead, everything works fine.

                      Did you have any more luck in the mean time?

                      J.HilkJ Offline
                      J.HilkJ Offline
                      J.Hilk
                      Moderators
                      wrote on last edited by
                      #15

                      @Marcus-Tillmanns interesting, I'm personally using a mix of static and dynamic libs (all qt based) on Mac and everything works just fine.

                      But I'm also using 5.15 and not Qt6


                      Be aware of the Qt Code of Conduct, when posting : https://forum.qt.io/topic/113070/qt-code-of-conduct


                      Q: What's that?
                      A: It's blue light.
                      Q: What does it do?
                      A: It turns blue.

                      V 1 Reply Last reply
                      0
                      • M Marcus Tillmanns

                        @Dariusz
                        I'm having the same issue (also M1 mac, haven't tried on other platforms yet). The problem seems to be that inside Qt code, the call to call dynamic_cast<>() fails for my object, even though it should work. The target class that it cannot dynamic_cast to is defined in a static library. When I change it to a dynamic library instead, everything works fine.

                        Did you have any more luck in the mean time?

                        SGaistS Offline
                        SGaistS Offline
                        SGaist
                        Lifetime Qt Champion
                        wrote on last edited by
                        #16

                        @Marcus-Tillmanns hi,

                        Any chances you are using plugins in your application ?

                        Interested in AI ? www.idiap.ch
                        Please read the Qt Code of Conduct - https://forum.qt.io/topic/113070/qt-code-of-conduct

                        1 Reply Last reply
                        0
                        • danttiD Offline
                          danttiD Offline
                          dantti
                          wrote on last edited by
                          #17

                          This is not related to ARM/Mac whatever, nor will happen before Qt 6.3.

                          The issue is that in 6.3 there's now an assert that checks if the receiver object and method "match", it works with lambdas as it's either incomplete or impossible to check because lambdas aren't part of the receiver type.

                          This happened to a code I replaced the old syntax and the issue was that some Parent class while destroying children of of them, had a signal being emitted on destructor, that called some functions and emitted back to the half destructed Parent hitting the assert.

                          What I did was to queue one the signals to allow the destructor to finish.

                          1 Reply Last reply
                          0
                          • J.HilkJ J.Hilk

                            @Marcus-Tillmanns interesting, I'm personally using a mix of static and dynamic libs (all qt based) on Mac and everything works just fine.

                            But I'm also using 5.15 and not Qt6

                            V Offline
                            V Offline
                            Vinny_Jones91
                            wrote on last edited by Vinny_Jones91
                            #18

                            @SGAIST hello.

                            I've encountered the same issue with Qt6.6.2 and yes, we're using plugins in our macOS application.

                            Looks like dymanic_cast fails to work correctly across dylib boundaries.
                            -flat_namespace compile option helps with dynamic_cast itself (and so, fixed the mentioned assert), but causes other issues for us.

                            If you could share any thoughts on how this may be fixed, that would be much appreciated.

                            SGaistS 1 Reply Last reply
                            0
                            • V Vinny_Jones91

                              @SGAIST hello.

                              I've encountered the same issue with Qt6.6.2 and yes, we're using plugins in our macOS application.

                              Looks like dymanic_cast fails to work correctly across dylib boundaries.
                              -flat_namespace compile option helps with dynamic_cast itself (and so, fixed the mentioned assert), but causes other issues for us.

                              If you could share any thoughts on how this may be fixed, that would be much appreciated.

                              SGaistS Offline
                              SGaistS Offline
                              SGaist
                              Lifetime Qt Champion
                              wrote on last edited by
                              #19

                              @Vinny_Jones91 hi and welcome to devnet,

                              Any chances you are using static libraries to build your plugins ?

                              Interested in AI ? www.idiap.ch
                              Please read the Qt Code of Conduct - https://forum.qt.io/topic/113070/qt-code-of-conduct

                              1 Reply Last reply
                              0
                              • I Offline
                                I Offline
                                Icaro
                                wrote on last edited by Icaro
                                #20

                                I had a similar issue and @SGaist question actually helped me.
                                My code was hitting the "called object is not the correct type class destructor..." assertion and I changed the library from static to dynamic and now it seems to work properly on MacOS.
                                Not sure what the issue is or if it is a bug that is already solved in more recent versions (I am currently using Qt6.4.2) but I will go for the dynamic library solution for now so I can move forward.
                                Thanks!

                                1 Reply Last reply
                                0

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