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Forum Update on Monday, May 27th 2025

segmentation fault

Scheduled Pinned Locked Moved Unsolved Mobile and Embedded
qt 4.8cross-compilingarmv7mqtt
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  • M Milav
    15 Oct 2019, 09:05

    @JonB

    but in gdb how i see "stack trace" ?

    what classes i use from List of classes of commands?

    please tell me

    J Online
    J Online
    jsulm
    Lifetime Qt Champion
    wrote on 15 Oct 2019, 09:10 last edited by
    #42

    @Milav In gdb enter bt and press enter after your app crashed

    https://forum.qt.io/topic/113070/qt-code-of-conduct

    M 1 Reply Last reply 15 Oct 2019, 09:26
    0
    • J jsulm
      15 Oct 2019, 09:10

      @Milav In gdb enter bt and press enter after your app crashed

      M Offline
      M Offline
      Milav
      wrote on 15 Oct 2019, 09:26 last edited by
      #43

      @jsulm

      i enter the gdb command as following .

      tdp0009@tdp0009-desktop:~/Teq_Projects/Aug_2019/HMI/Firmware/QT/Desktop_Application/11-oct/qt-mqtt-example/build-qt-mosquitto-Desktop-Release$ gdb qt-mosquitto 
      GNU gdb (Ubuntu 7.11.1-0ubuntu1~16.5) 7.11.1
      Copyright (C) 2016 Free Software Foundation, Inc.
      License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
      This is free software: you are free to change and redistribute it.
      There is NO WARRANTY, to the extent permitted by law.  Type "show copying"
      and "show warranty" for details.
      This GDB was configured as "x86_64-linux-gnu".
      Type "show configuration" for configuration details.
      For bug reporting instructions, please see:
      <http://www.gnu.org/software/gdb/bugs/>.
      Find the GDB manual and other documentation resources online at:
      <http://www.gnu.org/software/gdb/documentation/>.
      For help, type "help".
      Type "apropos word" to search for commands related to "word"...
      Reading symbols from qt-mosquitto...(no debugging symbols found)...done.
      (gdb) bt
      No stack.
      (gdb) 
      No stack.
      (gdb)
      
      J 1 Reply Last reply 15 Oct 2019, 10:25
      0
      • M Milav
        15 Oct 2019, 09:26

        @jsulm

        i enter the gdb command as following .

        tdp0009@tdp0009-desktop:~/Teq_Projects/Aug_2019/HMI/Firmware/QT/Desktop_Application/11-oct/qt-mqtt-example/build-qt-mosquitto-Desktop-Release$ gdb qt-mosquitto 
        GNU gdb (Ubuntu 7.11.1-0ubuntu1~16.5) 7.11.1
        Copyright (C) 2016 Free Software Foundation, Inc.
        License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
        This is free software: you are free to change and redistribute it.
        There is NO WARRANTY, to the extent permitted by law.  Type "show copying"
        and "show warranty" for details.
        This GDB was configured as "x86_64-linux-gnu".
        Type "show configuration" for configuration details.
        For bug reporting instructions, please see:
        <http://www.gnu.org/software/gdb/bugs/>.
        Find the GDB manual and other documentation resources online at:
        <http://www.gnu.org/software/gdb/documentation/>.
        For help, type "help".
        Type "apropos word" to search for commands related to "word"...
        Reading symbols from qt-mosquitto...(no debugging symbols found)...done.
        (gdb) bt
        No stack.
        (gdb) 
        No stack.
        (gdb)
        
        J Offline
        J Offline
        JonB
        wrote on 15 Oct 2019, 10:25 last edited by JonB
        #44

        @Milav
        Type run first to run your program! Then if it crashes type bt. You could type man gdb from the command-line, or help from within gdb like the message states. We had to learn to do that....

        M 1 Reply Last reply 15 Oct 2019, 11:40
        1
        • J JonB
          15 Oct 2019, 10:25

          @Milav
          Type run first to run your program! Then if it crashes type bt. You could type man gdb from the command-line, or help from within gdb like the message states. We had to learn to do that....

          M Offline
          M Offline
          Milav
          wrote on 15 Oct 2019, 11:40 last edited by
          #45

          @JonB

          thank you for your help.

          i run gdb from development host machine.

          here i send the output of that.

          tdp0009@tdp0009-desktop:~/Teq_Projects/Aug_2019/HMI/Phytec_Toolchain/arm-cortexa8-linux-gnueabihf/bin$ ./arm-cortexa8-linux-gnueabihf-gdb
          GNU gdb (GDB) 7.5
          Copyright (C) 2012 Free Software Foundation, Inc.
          License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
          This is free software: you are free to change and redistribute it.
          There is NO WARRANTY, to the extent permitted by law.  Type "show copying"
          and "show warranty" for details.
          This GDB was configured as "--host=i686-host-linux-gnu --target=arm-cortexa8-linux-gnueabihf".
          For bug reporting instructions, please see:
          <http://www.gnu.org/software/gdb/bugs/>.
          (gdb) target extended 192.168.5.52:2345
          Remote debugging using 192.168.5.52:2345
          (gdb) set remote exec-file /opt/milav/qt-mosquitto
          (gdb) run
          Starting program:  
          
          Program received signal SIGILL, Illegal instruction.
          0x404df208 in ?? ()
          (gdb) bt
          #0  0x404df208 in ?? ()
          Cannot access memory at address 0x0
          #1  0x404092c0 in ?? ()
          Cannot access memory at address 0x0
          #2  0x404092c0 in ?? ()
          Cannot access memory at address 0x0
          Backtrace stopped: previous frame identical to this frame (corrupt stack?)
          (gdb) 
          

          i think you got what you want.

          looking forward hearing from you.

          J 1 Reply Last reply 15 Oct 2019, 11:51
          0
          • M Milav
            15 Oct 2019, 11:40

            @JonB

            thank you for your help.

            i run gdb from development host machine.

            here i send the output of that.

            tdp0009@tdp0009-desktop:~/Teq_Projects/Aug_2019/HMI/Phytec_Toolchain/arm-cortexa8-linux-gnueabihf/bin$ ./arm-cortexa8-linux-gnueabihf-gdb
            GNU gdb (GDB) 7.5
            Copyright (C) 2012 Free Software Foundation, Inc.
            License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
            This is free software: you are free to change and redistribute it.
            There is NO WARRANTY, to the extent permitted by law.  Type "show copying"
            and "show warranty" for details.
            This GDB was configured as "--host=i686-host-linux-gnu --target=arm-cortexa8-linux-gnueabihf".
            For bug reporting instructions, please see:
            <http://www.gnu.org/software/gdb/bugs/>.
            (gdb) target extended 192.168.5.52:2345
            Remote debugging using 192.168.5.52:2345
            (gdb) set remote exec-file /opt/milav/qt-mosquitto
            (gdb) run
            Starting program:  
            
            Program received signal SIGILL, Illegal instruction.
            0x404df208 in ?? ()
            (gdb) bt
            #0  0x404df208 in ?? ()
            Cannot access memory at address 0x0
            #1  0x404092c0 in ?? ()
            Cannot access memory at address 0x0
            #2  0x404092c0 in ?? ()
            Cannot access memory at address 0x0
            Backtrace stopped: previous frame identical to this frame (corrupt stack?)
            (gdb) 
            

            i think you got what you want.

            looking forward hearing from you.

            J Online
            J Online
            jsulm
            Lifetime Qt Champion
            wrote on 15 Oct 2019, 11:51 last edited by
            #46

            @Milav said in segmentation fault:

            i think you got what you want

            Not really.
            Did you build the app in debug mode?

            https://forum.qt.io/topic/113070/qt-code-of-conduct

            M 1 Reply Last reply 15 Oct 2019, 11:56
            0
            • J jsulm
              15 Oct 2019, 11:51

              @Milav said in segmentation fault:

              i think you got what you want

              Not really.
              Did you build the app in debug mode?

              M Offline
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              Milav
              wrote on 15 Oct 2019, 11:56 last edited by
              #47

              @jsulm said in segmentation fault:

              Did you build the app in debug mode?

              yes i build the app in debug mode.

              1 Reply Last reply
              0
              • M Milav
                12 Oct 2019, 10:31

                Hello,

                I make a qt application for Embedded Custom Board and when i run the Application it gives segmentation fault.

                The application give segmentation fault due to following line.

                  mosq->subscribe(mosq->getMID(), topic.data(), 1);
                

                where mosq is define and declare as follow.

                class MainWindow : public QMainWindow
                {
                    Q_OBJECT
                
                public:
                    explicit MainWindow(QWidget *parent = 0);
                    ~MainWindow();
                
                private:
                    qtmosq* mosq = NULL;
                    QStringList subed;
                    QString currentTopic;
                    Ui::MainWindow *ui;
                --------
                --------
                --------
                };
                

                where qtmosq is define as follow..

                #include "QObject"
                #include "mosquittopp.h"
                
                using namespace mosqpp;
                
                class qtmosq : public QObject, public mosquittopp
                {
                    Q_OBJECT
                
                public:
                    qtmosq(const char *id = NULL, bool clean_session = true) : mosquittopp (id, clean_session) {MID = 0;}
                    ~qtmosq() {}
                
                    void on_connect(int result)
                    {
                        if (!result)
                        {
                            //subscribe(NULL, "$SYS/#", 2);
                            emit connected();
                        }
                        else
                            emit connectEnable();
                    }
                    void on_publish(int id)
                    {
                        MID++;
                        emit messageSent(true);
                    }
                    void on_subscribe(int mid, int qos_count, const int *granted_qos)
                    {
                        if (MID != 0)
                            emit subscribed();
                        MID++;
                    }
                ..........
                ..........
                ..........
                
                signals:
                    void connected();
                    void messageSent(bool);
                    void messageReceived(QString);
                    void connectEnable();
                    void subscribed();
                };
                

                so what is the reason behind for this fault.

                The same application are successfully run on Host Linux PC.

                I have use same mosquitto library in both the test.

                please help me to sort out this problem.

                I have send the reference link at where i used above program.

                Link :- Ref. Link

                Thank you
                Milav Soni

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                Pablo J. Rogina
                wrote on 15 Oct 2019, 16:51 last edited by
                #48

                @Milav said in segmentation fault:

                Link :- Ref. Link

                Could it be possible that you run such example AS IS, I mean just download/clone the code and try such example without any change.
                If you manage to make it work, then you'll have the foundation to start adapting it to whatever you need/desire.

                In addition, is there any compelling reason not to use the Qt MQTT module?
                Have you try any of the Qt MQTT examples?

                Upvote the answer(s) that helped you solve the issue
                Use "Topic Tools" button to mark your post as Solved
                Add screenshots via postimage.org
                Don't ask support requests via chat/PM. Please use the forum so others can benefit from the solution in the future

                M 1 Reply Last reply 16 Oct 2019, 04:59
                0
                • P Pablo J. Rogina
                  15 Oct 2019, 16:51

                  @Milav said in segmentation fault:

                  Link :- Ref. Link

                  Could it be possible that you run such example AS IS, I mean just download/clone the code and try such example without any change.
                  If you manage to make it work, then you'll have the foundation to start adapting it to whatever you need/desire.

                  In addition, is there any compelling reason not to use the Qt MQTT module?
                  Have you try any of the Qt MQTT examples?

                  M Offline
                  M Offline
                  Milav
                  wrote on 16 Oct 2019, 04:59 last edited by
                  #49

                  @Pablo-J-Rogina said in segmentation fault:

                  In addition, is there any compelling reason not to use the Qt MQTT module?
                  Have you try any of the Qt MQTT examples?

                  I use actually qt4.8.7 source for development so QMqtt is not build for this qt version, so that i do not use qmqtt class.

                  if you have any idea how to run QMqtt in qt 4.8.7 source than please tell me it is so helpful to me.

                  @Pablo-J-Rogina said in segmentation fault:

                  Could it be possible that you run such example AS IS, I mean just download/clone the code and try such example without any change.
                  If you manage to make it work, then you'll have the foundation to start adapting it to whatever you need/desire.

                  i actually tried same as is code for pc development and that is work fine.

                  but when i cross compiling the code for embedded target board than it gives segmentation error,

                  the difference between host pc and Embedded target board is only QT source.

                  Host pc => qmake (qt version 5.4.0 )
                  Embedded target => qmake (qt version 4.8.7)

                  hope you got my point.

                  if you have any query please tell me.

                  and please guys help me to sort out the problem.

                  i am also try another code for the same , but in that i have also suffer same problem.

                  Another code link :- link text

                  J P 2 Replies Last reply 16 Oct 2019, 05:16
                  0
                  • M Milav
                    16 Oct 2019, 04:59

                    @Pablo-J-Rogina said in segmentation fault:

                    In addition, is there any compelling reason not to use the Qt MQTT module?
                    Have you try any of the Qt MQTT examples?

                    I use actually qt4.8.7 source for development so QMqtt is not build for this qt version, so that i do not use qmqtt class.

                    if you have any idea how to run QMqtt in qt 4.8.7 source than please tell me it is so helpful to me.

                    @Pablo-J-Rogina said in segmentation fault:

                    Could it be possible that you run such example AS IS, I mean just download/clone the code and try such example without any change.
                    If you manage to make it work, then you'll have the foundation to start adapting it to whatever you need/desire.

                    i actually tried same as is code for pc development and that is work fine.

                    but when i cross compiling the code for embedded target board than it gives segmentation error,

                    the difference between host pc and Embedded target board is only QT source.

                    Host pc => qmake (qt version 5.4.0 )
                    Embedded target => qmake (qt version 4.8.7)

                    hope you got my point.

                    if you have any query please tell me.

                    and please guys help me to sort out the problem.

                    i am also try another code for the same , but in that i have also suffer same problem.

                    Another code link :- link text

                    J Online
                    J Online
                    jsulm
                    Lifetime Qt Champion
                    wrote on 16 Oct 2019, 05:16 last edited by
                    #50

                    @Milav OK, maybe we should start from the beginning.
                    Do you cross compile from PC to device?
                    Does the app crash in same way on host with Qt5?
                    Is it possible that you're mixing Qt4 and Qt5 on your target device? You can check this using "ldd EXECUTABLE" on your target.
                    Please do this on your target (in a terminal):

                    file /opt/milav/qt-mosquitto
                    ldd /opt/milav/qt-mosquitto
                    

                    and post the output here.

                    https://forum.qt.io/topic/113070/qt-code-of-conduct

                    M 2 Replies Last reply 16 Oct 2019, 05:39
                    0
                    • J jsulm
                      16 Oct 2019, 05:16

                      @Milav OK, maybe we should start from the beginning.
                      Do you cross compile from PC to device?
                      Does the app crash in same way on host with Qt5?
                      Is it possible that you're mixing Qt4 and Qt5 on your target device? You can check this using "ldd EXECUTABLE" on your target.
                      Please do this on your target (in a terminal):

                      file /opt/milav/qt-mosquitto
                      ldd /opt/milav/qt-mosquitto
                      

                      and post the output here.

                      M Offline
                      M Offline
                      Milav
                      wrote on 16 Oct 2019, 05:39 last edited by
                      #51

                      @jsulm said in segmentation fault:

                      OK, maybe we should start from the beginning.

                      Okay sure.

                      @jsulm said in segmentation fault:

                      Do you cross compile from PC to device?

                      Yes i cross compile the "qt-mosquitto" application for target (device) from qt creator (that is install on pc).

                      For cross compilng i have use qmake version 4.8.7.

                      and qt creator version is "Qt Creator 3.3.0 (opensource)"

                      and for v

                      @jsulm said in segmentation fault:

                      Does the app crash in same way on host with Qt5?

                      No, the application is not crash in PC.

                      In pc i have use same code but qmake vwersion is 5.4.0

                      @jsulm said in segmentation fault:

                      Is it possible that you're mixing Qt4 and Qt5 on your target device? You can check this using "ldd EXECUTABLE" on your target.

                      In target i have only qt 4 library and qmake are there.
                      i think there is no qt 5 component in target device.

                      @jsulm said in segmentation fault:

                      Please do this on your target (in a terminal):

                      sorry for this, but i have not ldd command on target device.
                      if it is necessary than tell i have install and cross compile it for target device.

                      sorry i dont know why this ldd cmd is not there in target device.

                      J 1 Reply Last reply 16 Oct 2019, 05:42
                      0
                      • M Milav
                        16 Oct 2019, 05:39

                        @jsulm said in segmentation fault:

                        OK, maybe we should start from the beginning.

                        Okay sure.

                        @jsulm said in segmentation fault:

                        Do you cross compile from PC to device?

                        Yes i cross compile the "qt-mosquitto" application for target (device) from qt creator (that is install on pc).

                        For cross compilng i have use qmake version 4.8.7.

                        and qt creator version is "Qt Creator 3.3.0 (opensource)"

                        and for v

                        @jsulm said in segmentation fault:

                        Does the app crash in same way on host with Qt5?

                        No, the application is not crash in PC.

                        In pc i have use same code but qmake vwersion is 5.4.0

                        @jsulm said in segmentation fault:

                        Is it possible that you're mixing Qt4 and Qt5 on your target device? You can check this using "ldd EXECUTABLE" on your target.

                        In target i have only qt 4 library and qmake are there.
                        i think there is no qt 5 component in target device.

                        @jsulm said in segmentation fault:

                        Please do this on your target (in a terminal):

                        sorry for this, but i have not ldd command on target device.
                        if it is necessary than tell i have install and cross compile it for target device.

                        sorry i dont know why this ldd cmd is not there in target device.

                        J Online
                        J Online
                        jsulm
                        Lifetime Qt Champion
                        wrote on 16 Oct 2019, 05:42 last edited by
                        #52

                        @Milav said in segmentation fault:

                        sorry i dont know why this ldd cmd is not there in target device

                        This is not unusual. On limited devices manufacturers usually remove everything not needed when using the device.
                        Is "file" command there?

                        https://forum.qt.io/topic/113070/qt-code-of-conduct

                        M 1 Reply Last reply 16 Oct 2019, 05:46
                        0
                        • J jsulm
                          16 Oct 2019, 05:42

                          @Milav said in segmentation fault:

                          sorry i dont know why this ldd cmd is not there in target device

                          This is not unusual. On limited devices manufacturers usually remove everything not needed when using the device.
                          Is "file" command there?

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                          M Offline
                          Milav
                          wrote on 16 Oct 2019, 05:46 last edited by
                          #53

                          @jsulm said in segmentation fault:

                          This is not unusual. On limited devices manufacturers usually remove everything not needed when using the device.
                          Is "file" command there?

                          Okay no problem.

                          actually "file" cmd also not in target device.

                          but in desktop pc i have "file" cmd so i execute file cmd with binary application file.

                          here i have show output of that .

                          tdp0009@tdp0009-desktop:~$ file qt-mosquitto 
                          qt-mosquitto: ELF 32-bit LSB executable, ARM, EABI5 version 1 (SYSV), dynamically linked, interpreter /lib/ld-, for GNU/Linux 2.6.32, not stripped
                          
                          

                          i think you got your answer from above result.

                          J 1 Reply Last reply 16 Oct 2019, 05:47
                          0
                          • M Milav
                            16 Oct 2019, 05:46

                            @jsulm said in segmentation fault:

                            This is not unusual. On limited devices manufacturers usually remove everything not needed when using the device.
                            Is "file" command there?

                            Okay no problem.

                            actually "file" cmd also not in target device.

                            but in desktop pc i have "file" cmd so i execute file cmd with binary application file.

                            here i have show output of that .

                            tdp0009@tdp0009-desktop:~$ file qt-mosquitto 
                            qt-mosquitto: ELF 32-bit LSB executable, ARM, EABI5 version 1 (SYSV), dynamically linked, interpreter /lib/ld-, for GNU/Linux 2.6.32, not stripped
                            
                            

                            i think you got your answer from above result.

                            J Online
                            J Online
                            jsulm
                            Lifetime Qt Champion
                            wrote on 16 Oct 2019, 05:47 last edited by
                            #54

                            @Milav said in segmentation fault:

                            32-bit LSB executable, ARM, EABI5

                            Looks good if that's what your target device CPU is

                            https://forum.qt.io/topic/113070/qt-code-of-conduct

                            M 2 Replies Last reply 16 Oct 2019, 05:52
                            0
                            • J jsulm
                              16 Oct 2019, 05:47

                              @Milav said in segmentation fault:

                              32-bit LSB executable, ARM, EABI5

                              Looks good if that's what your target device CPU is

                              M Offline
                              M Offline
                              Milav
                              wrote on 16 Oct 2019, 05:52 last edited by
                              #55

                              @jsulm said in segmentation fault:

                              Looks good if that's what your target device CPU is

                              yes. it is ARM based 32-bit CPU.

                              1 Reply Last reply
                              0
                              • J jsulm
                                16 Oct 2019, 05:16

                                @Milav OK, maybe we should start from the beginning.
                                Do you cross compile from PC to device?
                                Does the app crash in same way on host with Qt5?
                                Is it possible that you're mixing Qt4 and Qt5 on your target device? You can check this using "ldd EXECUTABLE" on your target.
                                Please do this on your target (in a terminal):

                                file /opt/milav/qt-mosquitto
                                ldd /opt/milav/qt-mosquitto
                                

                                and post the output here.

                                M Offline
                                M Offline
                                Milav
                                wrote on 16 Oct 2019, 06:08 last edited by
                                #56

                                @jsulm said in segmentation fault:

                                ldd /opt/milav/qt-mosquitto

                                hello ,

                                i explore and find some of the cmd for ldd.

                                here i have show the output for ldd qt-mosquitto/

                                  Shared library: [libmosquittopp.so.1]
                                 0x00000001 (NEEDED)                     Shared library: [libmosquitto.so.1]
                                 0x00000001 (NEEDED)                     Shared library: [libdl.so.2]
                                 0x00000001 (NEEDED)                     Shared library: [librt.so.1]
                                 0x00000001 (NEEDED)                     Shared library: [libpthread.so.0]
                                 0x00000001 (NEEDED)                     Shared library: [libstdc++.so.6]
                                 0x00000001 (NEEDED)                     Shared library: [libm.so.6]
                                 0x00000001 (NEEDED)                     Shared library: [libgcc_s.so.1]
                                 0x00000001 (NEEDED)                     Shared library: [libc.so.6]
                                 0x00000001 (NEEDED)                     Shared library: [ld-linux-armhf.so.3]
                                
                                

                                hope now you got your answer.

                                1 Reply Last reply
                                0
                                • J jsulm
                                  16 Oct 2019, 05:47

                                  @Milav said in segmentation fault:

                                  32-bit LSB executable, ARM, EABI5

                                  Looks good if that's what your target device CPU is

                                  M Offline
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                                  Milav
                                  wrote on 16 Oct 2019, 09:10 last edited by
                                  #57

                                  @jsulm

                                  Hello, have you got any solution?

                                  J 1 Reply Last reply 16 Oct 2019, 10:26
                                  0
                                  • M Milav
                                    16 Oct 2019, 09:10

                                    @jsulm

                                    Hello, have you got any solution?

                                    J Online
                                    J Online
                                    jsulm
                                    Lifetime Qt Champion
                                    wrote on 16 Oct 2019, 10:26 last edited by
                                    #58

                                    @Milav Did you try to cross compile a simple application and run it on your device?

                                    https://forum.qt.io/topic/113070/qt-code-of-conduct

                                    M 1 Reply Last reply 16 Oct 2019, 10:41
                                    1
                                    • J jsulm
                                      16 Oct 2019, 10:26

                                      @Milav Did you try to cross compile a simple application and run it on your device?

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                                      Milav
                                      wrote on 16 Oct 2019, 10:41 last edited by
                                      #59

                                      @jsulm

                                      yes, without mqtt module , i tried lot of application and it is working very fine..

                                      J 1 Reply Last reply 16 Oct 2019, 11:25
                                      0
                                      • M Milav
                                        16 Oct 2019, 10:41

                                        @jsulm

                                        yes, without mqtt module , i tried lot of application and it is working very fine..

                                        J Online
                                        J Online
                                        jsulm
                                        Lifetime Qt Champion
                                        wrote on 16 Oct 2019, 11:25 last edited by
                                        #60

                                        @Milav Then I suggest to start with a minimal application and add mqtt functionality in small pieces to see when it starts to crash.

                                        https://forum.qt.io/topic/113070/qt-code-of-conduct

                                        1 Reply Last reply
                                        1
                                        • M Milav
                                          16 Oct 2019, 04:59

                                          @Pablo-J-Rogina said in segmentation fault:

                                          In addition, is there any compelling reason not to use the Qt MQTT module?
                                          Have you try any of the Qt MQTT examples?

                                          I use actually qt4.8.7 source for development so QMqtt is not build for this qt version, so that i do not use qmqtt class.

                                          if you have any idea how to run QMqtt in qt 4.8.7 source than please tell me it is so helpful to me.

                                          @Pablo-J-Rogina said in segmentation fault:

                                          Could it be possible that you run such example AS IS, I mean just download/clone the code and try such example without any change.
                                          If you manage to make it work, then you'll have the foundation to start adapting it to whatever you need/desire.

                                          i actually tried same as is code for pc development and that is work fine.

                                          but when i cross compiling the code for embedded target board than it gives segmentation error,

                                          the difference between host pc and Embedded target board is only QT source.

                                          Host pc => qmake (qt version 5.4.0 )
                                          Embedded target => qmake (qt version 4.8.7)

                                          hope you got my point.

                                          if you have any query please tell me.

                                          and please guys help me to sort out the problem.

                                          i am also try another code for the same , but in that i have also suffer same problem.

                                          Another code link :- link text

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                                          Pablo J. Rogina
                                          wrote on 16 Oct 2019, 12:35 last edited by
                                          #61

                                          @Milav said in segmentation fault:

                                          the difference between host pc and Embedded target board is only QT source.
                                          Host pc => qmake (qt version 5.4.0 )
                                          Embedded target => qmake (qt version 4.8.7)

                                          You should have stated these settings from the very beginning... :-)

                                          Anyway, could it be possible that you build Qt 4.8.7 for PC (host) and build your example again with that Qt version and run in PC to see what happens.

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                                          16 Oct 2019, 05:39

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