/********************************************************************************

 *       libQt5Core.so: undefined reference to `dlclose@GLIBC_2.4'

 * 说明：

 *     在编译QT 5.8的程序的时遇到找不到库的问题。

 *

 *                                                2017-6-8 深圳 龙华樟坑村 曾剑锋

 *******************************************************************************/

一、参考文档：

    . 树莓派交叉编译qt5.5的问题

        http://tieba.baidu.com/p/4327053176

二、编译报错：

    ::: Running steps for project zengjfTest...

    ::: Starting: "/home/zengjf/zengjf/zengjfos/Qt5.8/rootfs/usr/local/qt5.8/bin/qmake" /home/zengjf/zengjf/zengjfos/Qt5.8Demo/zengjfTest/zengjfTest.pro -r -spec linux-arm-gnueabihf-g++

    ::: The process "/home/zengjf/zengjf/zengjfos/Qt5.8/rootfs/usr/local/qt5.8/bin/qmake" exited normally.

    ::: Starting: "/usr/bin/make"

    arm-linux-gnueabihf-g++ --sysroot=/home/zengjf/zengjf/zengjfos/Qt5./rootfs -Wl,-O1 -Wl,-rpath,/usr/local/qt5./lib -o zengjfTest main.o mainwindow.o moc_mainwindow.o   -L/home/zengjf/zengjf/zengjfos/Qt5./rootfs/usr/local/qt5./lib -lQt5Widgets -L/home/zengjf/zengjf/zengjfos/Qt5./tslib-1.4/__install/lib -lQt5Gui -lQt5Core -lpthread

    /usr/lib/gcc-cross/arm-linux-gnueabihf//../../../../arm-linux-gnueabihf/bin/ld: warning: libdl.so., needed by /home/zengjf/zengjf/zengjfos/Qt5./rootfs/usr/local/qt5./lib/libQt5Core.so, not found (try using -rpath or -rpath-link)

    Makefile:: recipe for target 'zengjfTest' failed

    /usr/lib/gcc-cross/arm-linux-gnueabihf//../../../../arm-linux-gnueabihf/bin/ld: warning: librt.so., needed by /home/zengjf/zengjf/zengjfos/Qt5./rootfs/usr/local/qt5./lib/libQt5Core.so, not found (try using -rpath or -rpath-link)

    /home/zengjf/zengjf/zengjfos/Qt5./rootfs/usr/local/qt5./lib/libQt5Core.so: undefined reference to `clock_gettime@GLIBC_2.'

    /home/zengjf/zengjf/zengjfos/Qt5./rootfs/usr/local/qt5./lib/libQt5Core.so: undefined reference to `dlopen@GLIBC_2.'

    /home/zengjf/zengjf/zengjfos/Qt5./rootfs/usr/local/qt5./lib/libQt5Core.so: undefined reference to `dlsym@GLIBC_2.'

    /home/zengjf/zengjf/zengjfos/Qt5./rootfs/usr/local/qt5./lib/libQt5Core.so: undefined reference to `dlerror@GLIBC_2.'

    /home/zengjf/zengjf/zengjfos/Qt5./rootfs/usr/local/qt5./lib/libQt5Core.so: undefined reference to `dlclose@GLIBC_2.'

    collect2: error: ld returned  exit status

    make: *** [zengjfTest] Error

    ::: The process "/usr/bin/make" exited with code .

    Error while building/deploying project zengjfTest (kit: 5.8-ARM)

        When executing step "Make"

        ::: Elapsed time: :.

    ::: Running steps for project zengjfTest...

    ::: Starting: "/home/zengjf/zengjf/zengjfos/Qt5.8/rootfs/usr/local/qt5.8/bin/qmake" /home/zengjf/zengjf/zengjfos/Qt5.8Demo/zengjfTest/zengjfTest.pro -r -spec linux-arm-gnueabihf-g++

    ::: The process "/home/zengjf/zengjf/zengjfos/Qt5.8/rootfs/usr/local/qt5.8/bin/qmake" exited normally.

    ::: Starting: "/usr/bin/make"

    arm-linux-gnueabihf-g++ --sysroot=/home/zengjf/zengjf/zengjfos/Qt5./rootfs -Wl,-O1 -Wl,-rpath,/usr/local/qt5./lib -o zengjfTest main.o mainwindow.o moc_mainwindow.o   -L/home/zengjf/zengjf/zengjfos/Qt5./rootfs/usr/local/qt5./lib -lQt5Widgets -L/home/zengjf/zengjf/zengjfos/Qt5./tslib-1.4/__install/lib -lQt5Gui -lQt5Core -lpthread

    /usr/lib/gcc-cross/arm-linux-gnueabihf//../../../../arm-linux-gnueabihf/bin/ld: warning: libdl.so., needed by /home/zengjf/zengjf/zengjfos/Qt5./rootfs/usr/local/qt5./lib/libQt5Core.so, not found (try using -rpath or -rpath-link)

    Makefile:: recipe for target 'zengjfTest' failed

    /usr/lib/gcc-cross/arm-linux-gnueabihf//../../../../arm-linux-gnueabihf/bin/ld: warning: librt.so., needed by /home/zengjf/zengjf/zengjfos/Qt5./rootfs/usr/local/qt5./lib/libQt5Core.so, not found (try using -rpath or -rpath-link)

    /home/zengjf/zengjf/zengjfos/Qt5./rootfs/usr/local/qt5./lib/libQt5Core.so: undefined reference to `clock_gettime@GLIBC_2.'

    /home/zengjf/zengjf/zengjfos/Qt5./rootfs/usr/local/qt5./lib/libQt5Core.so: undefined reference to `dlopen@GLIBC_2.'

    /home/zengjf/zengjf/zengjfos/Qt5./rootfs/usr/local/qt5./lib/libQt5Core.so: undefined reference to `dlsym@GLIBC_2.'

    /home/zengjf/zengjf/zengjfos/Qt5./rootfs/usr/local/qt5./lib/libQt5Core.so: undefined reference to `dlerror@GLIBC_2.'

    /home/zengjf/zengjf/zengjfos/Qt5./rootfs/usr/local/qt5./lib/libQt5Core.so: undefined reference to `dlclose@GLIBC_2.'

    collect2: error: ld returned  exit status

    make: *** [zengjfTest] Error

    ::: The process "/usr/bin/make" exited with code .

    Error while building/deploying project zengjfTest (kit: 5.8-ARM)

        When executing step "Make"

        ::: Elapsed time: :.

三、解决办法：

    将相关的warning找不到的lib，放到对应的lib下去就可以了。