Qt serial port program crashes when run on another system

Question

I modified this code on a Windows 10 PC, and it compiled and ran without crashing.

#include <QtSerialPort/QSerialPort>

#include <QTextStream>
#include <QCoreApplication>
#include <QFile>
#include <QStringList>

QT_USE_NAMESPACE

int main(int argc, char *argv[])
{
    QCoreApplication coreApplication(argc, argv);
    int argumentCount = QCoreApplication::arguments().size();
    QStringList argumentList = QCoreApplication::arguments();

    QTextStream standardOutput(stdout);

    if (argumentCount == 1) {
        standardOutput << QObject::tr("Usage: %1 <serialportname>     [baudrate]").arg(argumentList.first()) << endl;
        return 1;
    }

    QSerialPort serialPort;
    QString serialPortName = argumentList.at(1);
    serialPort.setPortName(serialPortName);

    int serialPortBaudRate = (argumentCount > 2) ? argumentList.at(2).toInt() : QSerialPort::Baud9600;
    serialPort.setBaudRate(serialPortBaudRate);

    if (!serialPort.open(QIODevice::WriteOnly)) {
        standardOutput << QObject::tr("Failed to open port %1, error:     %2").arg(serialPortName).arg(serialPort.errorString()) << endl;
        return 1;
    }

    QFile dataFile("C:\\SerialCommand.dat");
    if (!dataFile.open(QIODevice::ReadOnly)) {
        standardOutput << QObject::tr("Failed to open file for reading") <<     endl;
        return 1;
    }

    QByteArray writeData(dataFile.readAll());
    dataFile.close();

    if (writeData.isEmpty()) {
        standardOutput << QObject::tr("Either no data was currently available on the standard input for reading, or an error occurred for port %1, error: %2").arg(serialPortName).arg(serialPort.errorString()) << endl;
        return 1;
    }

    qint64 bytesWritten = serialPort.write(writeData);

    if (bytesWritten == -1) {
        standardOutput << QObject::tr("Failed to write the data to port %1, error: %2").arg(serialPortName).arg(serialPort.errorString()) << endl;
        return 1;
    } else if (bytesWritten != writeData.size()) {
        standardOutput << QObject::tr("Failed to write all the data to port %1, error: %2").arg(serialPortName).arg(serialPort.errorString()) << endl;
        return 1;
    } else if (!serialPort.waitForBytesWritten(5000)) {
        standardOutput << QObject::tr("Operation timed out or an error occurred for port %1, error: %2").arg(serialPortName).arg(serialPort.errorString()) << endl;
        return 1;
    }

    standardOutput << QObject::tr("Data successfully sent to port %1").arg(serialPortName) << endl;

    printf("\n\ntest");

    return 0;
}

I set Qt to release mode, and packaged the application with the following .dll files:

1. msvcp120d.dll
2. msvcr120d.dll
3. Qt5Core.dll
4. Qt5Cored.dll
5. Qt5SerialPort.dll
6. Qt5SerialPortd.dll
7. Qt5Widgets.dll
8. qwindows.dll

When I ran the application on another system (also windows 10), the program crashes immediately - and yes, I did move SerialCommand.dat to its correct location on the C drive. Any thoughts?

Answer 1

You're packaging the debug versions of the dlls (ending with a d ) instead of release ones.

Read the Qt deployment docs , especially the last part (from "Application Dependencies" to the end).

The dependency walker helps find the actual dependencies, and in theory windeployqt should automate the work of creating a release dir with all the files you need.

See also this other question , but it's for an app using QML, so it's more complex than your case.