Ubuntu18.04下，QT5移植到ARM板上运行程序发生异常：could not find or load the Qt platform plugin "linuxfb"原因

作者：陈浩
特别助理：游成伟
QT移植库文件后，运行qt可执行程序，结果显示如下异常：

/home/appbin # ./armBoardLight 
This application failed to start because it could not find or load the Qt platform plugin "linuxfb"
in "/home/qt/plugins".

Available platform plugins are: linuxfb, minimal, offscreen, vnc.

Reinstalling the application may fix this problem.
Aborted
/home/appbin # 

在试过重新在上位机编译QT源码，重新移植QT动态库文件后，任然出现这种问题。
在arm下位机配置文件/etc/profile后面添加如下调试环境变量：

export QT_DEBUG_LUGINS=1

保存退出，然后重启下位机arm板后，上位机屏幕显示如下信息：

/home/appbin # ./armBoardLight 
QFactoryLoader::QFactoryLoader() checking directory path "/home/qt/plugins" ...
QFactoryLoader::QFactoryLoader() checking directory path "/home/appbin" ...
QFactoryLoader::QFactoryLoader() looking at "/home/appbin/armBoardLight"
"Failed to extract plugin meta data from '/home/appbin/armBoardLight'" 
         not a plugin
QFactoryLoader::QFactoryLoader() checking directory path "/home/qt/plugins/platforms" ...
QFactoryLoader::QFactoryLoader() looking at "/home/qt/plugins/platforms/libqlinuxfb.so"
Found metadata in lib /home/qt/plugins/platforms/libqlinuxfb.so, metadata=
{
    "IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
    "MetaData": {
        "Keys": [
            "linuxfb"
        ]
    },
    "className": "QLinuxFbIntegrationPlugin",
    "debug": false,
    "version": 329989
}


Got keys from plugin meta data ("linuxfb")
QFactoryLoader::QFactoryLoader() looking at "/home/qt/plugins/platforms/libqminimal.so"
Found metadata in lib /home/qt/plugins/platforms/libqminimal.so, metadata=
{
    "IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
    "MetaData": {
        "Keys": [
            "minimal"
        ]
    },
    "className": "QMinimalIntegrationPlugin",
    "debug": false,
    "version": 329989
}


Got keys from plugin meta data ("minimal")
QFactoryLoader::QFactoryLoader() looking at "/home/qt/plugins/platforms/libqoffscreen.so"
Found metadata in lib /home/qt/plugins/platforms/libqoffscreen.so, metadata=
{
    "IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
    "MetaData": {
        "Keys": [
            "offscreen"
        ]
    },
    "className": "QOffscreenIntegrationPlugin",
    "debug": false,
    "version": 329989
}


Got keys from plugin meta data ("offscreen")
QFactoryLoader::QFactoryLoader() looking at "/home/qt/plugins/platforms/libqvnc.so"
Found metadata in lib /home/qt/plugins/platforms/libqvnc.so, metadata=
{
    "IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
    "MetaData": {
        "Keys": [
            "vnc"
        ]
    },
    "className": "QVncIntegrationPlugin",
    "debug": false,
    "version": 329989
}


Got keys from plugin meta data ("vnc")
QFactoryLoader::QFactoryLoader() checking directory path "/home/appbin/platforms" ...
Cannot load library /home/qt/plugins/platforms/libqlinuxfb.so: (libts-1.0.so.0: cannot open shared object file: No such file or directory)
QLibraryPrivate::loadPlugin failed on "/home/qt/plugins/platforms/libqlinuxfb.so" : "Cannot load library /home/qt/plugins/platforms/libqlinuxfb.so: (libts-1.0.so.0: cannot open shared object file: No such file or directory)"
This application failed to start because it could not find or load the Qt platform plugin "linuxfb"
in "/home/qt/plugins".

Available platform plugins are: linuxfb, minimal, offscreen, vnc.

Reinstalling the application may fix this problem.
Aborted

仔细阅读以上调试信息，发现发生真正错误处：

Cannot load library /home/qt/plugins/platforms/libqlinuxfb.so: (libts-1.0.so.0: cannot open shared object file: No such file or directory)

发现原因是缺少动态库文件libts-1.0.so.0
在上位机交叉编译器里找到这个动态库的软链接和硬链接文件，全部移植到arm板下位机，然后重启下位机，至此，下位机成功运行qt可执行文件。