1) 当我从命令行启动 Understand 时，我看到以下内容。一切正常。：
[me@box1 ~]# understand
2）在“入门”标题下的“入门”选项卡上：
当我单击“了解帮助...”、“了解常见问题...”、“了解 Perl API 帮助...”、“了解 Python API 帮助...”和“SciTools 支持...”中的任何链接以及“帮助”菜单中的相同链接时，以下错误会添加到终端窗口，并且什么也不会发生：
[me@box1 4.4.19 vpn-client]# understand
kde-open5: /home/me/bin/scitools/bin/linux64/libQt5Core.so.5: version 'Qt_5.10' not found (required by kde-open5)
kde-open5: /home/me/bin/scitools/bin/linux64/libQt5Core.so.5: version 'Qt_5.10' not found (required by /usr/lib/libKF5KIOWidgets.so.5)
kde-open5: /home/me/bin/scitools/bin/linux64/libQt5Core.so.5: version 'Qt_5.10' not found (required by /usr/lib/libKF5KIOCore.so.5)
kde-open5: /home/me/bin/scitools/bin/linux64/libQt5Core.so.5: version 'Qt_5.10' not found (required by /usr/lib/libKF5I18n.so.5)
kde-open5: /home/me/bin/scitools/bin/linux64/libQt5Core.so.5: version 'Qt_5.10' not found (required by /usr/lib/libKF5CoreAddons.so.5)
kde-open5: /home/me/bin/scitools/bin/linux64/libQt5Core.so.5: version 'Qt_5.10' not found (required by /usr/lib/libKF5JobWidgets.so.5)
kde-open5: /home/me/bin/scitools/bin/linux64/libQt5Core.so.5: version 'Qt_5.10' not found (required by /usr/lib/libKF5Service.so.5)
kde-open5: /home/me/bin/scitools/bin/linux64/libQt5Core.so.5: version 'Qt_5.10' not found (required by /usr/lib/libKF5Completion.so.5)
kde-open5: /home/me/bin/scitools/bin/linux64/libQt5Core.so.5: version 'Qt_5.10' not found (required by /usr/lib/libKF5IconThemes.so.5)
kde-open5: /home/me/bin/scitools/bin/linux64/libQt5Core.so.5: version 'Qt_5.10' not found (required by /usr/lib/libKF5WindowSystem.so.5)
kde-open5: /home/me/bin/scitools/bin/linux64/libQt5Core.so.5: version 'Qt_5.10' not found (required by /usr/lib/libKF5ConfigWidgets.so.5)
kde-open5: /home/me/bin/scitools/bin/linux64/libQt5Core.so.5: version 'Qt_5.10' not found (required by /usr/lib/libKF5WidgetsAddons.so.5)
kde-open5: /home/me/bin/scitools/bin/linux64/libQt5Core.so.5: version 'Qt_5.10' not found (required by /usr/lib/libKF5ConfigGui.so.5)
kde-open5: /home/me/bin/scitools/bin/linux64/libQt5Core.so.5: version 'Qt_5.10' not found (required by /usr/lib/libKF5ConfigCore.so.5)
kde-open5: /home/me/bin/scitools/bin/linux64/libQt5Core.so.5: version 'Qt_5.10' not found (required by /usr/lib/libQt5DBus.so.5)
kde-open5: /home/me/bin/scitools/bin/linux64/libQt5Core.so.5: version 'Qt_5.10' not found (required by /usr/lib/libKF5DBusAddons.so.5)
kde-open5: /home/me/bin/scitools/bin/linux64/libQt5Core.so.5: version 'Qt_5.10' not found (required by /usr/lib/libKF5Auth.so.5)
kde-open5: /home/me/bin/scitools/bin/linux64/libQt5Core.so.5: version 'Qt_5.10' not found (required by /usr/lib/libQt5X11Extras.so.5)
kde-open5: /home/me/bin/scitools/bin/linux64/libQt5Core.so.5: version 'Qt_5.10' not found (required by /usr/lib/libQt5Svg.so.5)
kde-open5: /home/me/bin/scitools/bin/linux64/libQt5Core.so.5: version 'Qt_5.10' not found (required by /usr/lib/libKF5Archive.so.5)
kde-open5: /home/me/bin/scitools/bin/linux64/libQt5Core.so.5: version 'Qt_5.10' not found (required by /usr/lib/libKF5ItemViews.so.5)
kde-open5: /home/me/bin/scitools/bin/linux64/libQt5Core.so.5: version 'Qt_5.10' not found (required by /usr/lib/libKF5Codecs.so.5)
kde-open5: /home/me/bin/scitools/bin/linux64/libQt5Core.so.5: version 'Qt_5.10' not found (required by /usr/lib/libKF5GuiAddons.so.5)
3)qmake通知我Qt v5.10.1已由我的发行版(Arch Linux)安装：
[me@box1 ~]# qmake -version
QMake version 3.1
Using Qt version 5.10.1 in /usr/lib
4)readelf通知我（并确认的qmake输出）我的发行版安装了 Qt Core v5.10.1：
[me@box1 ~]# readelf -V /usr/lib/libQt5Core.so.5.10.1 | grep -ie 'Qt_5\.'
d7c: 9h(Qt_5.5) bh(Qt_5.7) e (Qt_5.10) 3 (Qt_5)
d80: 5h(Qt_5.1) ch(Qt_5.8) 7h(Qt_5.3) 8h(Qt_5.4)
d84: ah(Qt_5.6) dh(Qt_5.9) 4h(Qt_5.0) 6h(Qt_5.2)
149c: 3 (Qt_5) e (Qt_5.10) 3 (Qt_5) 2 (Qt_5_PRIVATE_API)
14c0: 3 (Qt_5) 4 (Qt_5.0) 3 (Qt_5) 3 (Qt_5)
14c4: 3 (Qt_5) 3 (Qt_5) 5 (Qt_5.1) 3 (Qt_5)
14c8: 6 (Qt_5.2) 2 (Qt_5_PRIVATE_API) 7 (Qt_5.3) 3 (Qt_5)
14cc: 8 (Qt_5.4) 3 (Qt_5) 3 (Qt_5) 3 (Qt_5)
14d0: 3 (Qt_5) 3 (Qt_5) 9 (Qt_5.5) 3 (Qt_5)
14d4: 3 (Qt_5) a (Qt_5.6) 3 (Qt_5) 3 (Qt_5)
14d8: 3 (Qt_5) 2 (Qt_5_PRIVATE_API) b (Qt_5.7) 3 (Qt_5)
14dc: 2 (Qt_5_PRIVATE_API) 3 (Qt_5) c (Qt_5.8) 3 (Qt_5)
14e0: 3 (Qt_5) d (Qt_5.9) 3 (Qt_5) 2 (Qt_5_PRIVATE_API)
0x0054: Rev: 1 Flags: none Index: 4 Cnt: 2 Name: Qt_5.0
0x0078: Rev: 1 Flags: none Index: 5 Cnt: 2 Name: Qt_5.1
0x0094: Parent 1: Qt_5.0
0x009c: Rev: 1 Flags: none Index: 6 Cnt: 2 Name: Qt_5.2
0x00b8: Parent 1: Qt_5.1
0x00c0: Rev: 1 Flags: none Index: 7 Cnt: 2 Name: Qt_5.3
0x00dc: Parent 1: Qt_5.2
0x00e4: Rev: 1 Flags: none Index: 8 Cnt: 2 Name: Qt_5.4
0x0100: Parent 1: Qt_5.3
0x0108: Rev: 1 Flags: none Index: 9 Cnt: 2 Name: Qt_5.5
0x0124: Parent 1: Qt_5.4
0x012c: Rev: 1 Flags: none Index: 10 Cnt: 2 Name: Qt_5.6
0x0148: Parent 1: Qt_5.5
0x0150: Rev: 1 Flags: none Index: 11 Cnt: 2 Name: Qt_5.7
0x016c: Parent 1: Qt_5.6
0x0174: Rev: 1 Flags: none Index: 12 Cnt: 2 Name: Qt_5.8
0x0190: Parent 1: Qt_5.7
0x0198: Rev: 1 Flags: none Index: 13 Cnt: 2 Name: Qt_5.9
0x01b4: Parent 1: Qt_5.8
0x01bc: Rev: 1 Flags: none Index: 14 Cnt: 2 Name: Qt_5.10
0x01d8: Parent 1: Qt_5.9
5)readelf通知我 Understand 随 Qt v5.6 一起提供：
[me@box1 ~]# readelf -V /home/me/bin/scitools/bin/linux64/libQt5Core.so.5 | grep -ie 'Qt_5\.'
9e8: 3 (Qt_5) 3 (Qt_5) 4 (Qt_5.0) 2 (Qt_5_PRIVATE_API)
9ec: 3 (Qt_5) 3 (Qt_5) 5 (Qt_5.1) 3 (Qt_5)
9f0: 6 (Qt_5.2) 3 (Qt_5) 2 (Qt_5_PRIVATE_API) 3 (Qt_5)
9f4: 2 (Qt_5_PRIVATE_API) 7 (Qt_5.3) 3 (Qt_5) 8 (Qt_5.4)
9f8: 3 (Qt_5) 3 (Qt_5) 9 (Qt_5.5) 3 (Qt_5)
9fc: 3 (Qt_5) 3 (Qt_5) a (Qt_5.6) 2 (Qt_5_PRIVATE_API)
d90: 3 (Qt_5) 5h(Qt_5.1) 4h(Qt_5.0) a (Qt_5.6)
d94: 8h(Qt_5.4) 9h(Qt_5.5) 6h(Qt_5.2) 7h(Qt_5.3)
0x0054: Rev: 1 Flags: none Index: 4 Cnt: 2 Name: Qt_5.0
0x0078: Rev: 1 Flags: none Index: 5 Cnt: 2 Name: Qt_5.1
0x0094: Parent 1: Qt_5.0
0x009c: Rev: 1 Flags: none Index: 6 Cnt: 2 Name: Qt_5.2
0x00b8: Parent 1: Qt_5.1
0x00c0: Rev: 1 Flags: none Index: 7 Cnt: 2 Name: Qt_5.3
0x00dc: Parent 1: Qt_5.2
0x00e4: Rev: 1 Flags: none Index: 8 Cnt: 2 Name: Qt_5.4
0x0100: Parent 1: Qt_5.3
0x0108: Rev: 1 Flags: none Index: 9 Cnt: 2 Name: Qt_5.5
0x0124: Parent 1: Qt_5.4
0x012c: Rev: 1 Flags: none Index: 10 Cnt: 2 Name: Qt_5.6
0x0148: Parent 1: Qt_5.5
6)ldd通知我 Understand 将使用其发布的 Qt 版本：
[me@box1 ~]# ldd /home/me/bin/scitools/bin/linux64/understand.bin | grep -ie 'scitools'
libQt5Concurrent.so.5 => /home/me/bin/scitools/bin/linux64/libQt5Concurrent.so.5 (0x00007f0a63b77000)
libQt5Sql.so.5 => /home/me/bin/scitools/bin/linux64/libQt5Sql.so.5 (0x00007f0a63af9000)
libQt5Network.so.5 => /home/me/bin/scitools/bin/linux64/libQt5Network.so.5 (0x00007f0a624dd000)
libQt5Xml.so.5 => /home/me/bin/scitools/bin/linux64/libQt5Xml.so.5 (0x00007f0a63abd000)
libQt5PrintSupport.so.5 => /home/me/bin/scitools/bin/linux64/libQt5PrintSupport.so.5 (0x00007f0a63a4d000)
libastyle.so => /home/me/bin/scitools/bin/linux64/libastyle.so (0x00007f0a6229a000)
libQt5Widgets.so.5 => /home/me/bin/scitools/bin/linux64/libQt5Widgets.so.5 (0x00007f0a61c12000)
libQt5Gui.so.5 => /home/me/bin/scitools/bin/linux64/libQt5Gui.so.5 (0x00007f0a61732000)
libQt5Core.so.5 => /home/me/bin/scitools/bin/linux64/libQt5Core.so.5 (0x00007f0a6117a000)
understand7）启动的Bash脚本understand.bin包含以下内容：
#!/bin/bash
scriptdir=`dirname $0`
export LD_LIBRARY_PATH=$scriptdir
unset QT_PLUGIN_PATH
$0.bin "$@"
8）复制understand脚本并添加以下行，echo "\$LD_LIBRARY_PATH after === $LD_LIBRARY_PATH"显示其设置为：
$LD_LIBRARY_PATH after === /home/me/bin/scitools/bin/linux64
9) 显然，抛出错误的库正在寻找 Qt v5.10 Core 库。但却找到了 Understand 附带的 Qt v5.6 Core 库。
因此我使用以下命令添加了指向 understand 目录的符号链接：
[me@box1 ~]# ln -sf /usr/lib/libQt5Core.so.5.10.1 /home/me/bin/scitools/bin/linux64/libQt5Core.so.5.10
但这并没有改变什么。
然后，我继续更改“理解” Bash 脚本的副本（understand-test），并将行更改export LD_LIBRARY_PATH=$scriptdir为export LD_LIBRARY_PATH=$scriptdir:/usr/lib。但这也没有改变任何东西。
尽管 /home/me/bin/scitools/bin/linux64/libQt5Core.so.5 （v5.6）正在使用中，我该怎么做才能使库像 /usr/lib/libKF5KIOWidgets.so.5， /usr/lib/libKF5KIOCore.so.5等查找并使用 v5.10.1 /usr/lib/libQt5Core.so.5.10.1 ？
答案1
通常，库在各个次要版本之间是向后兼容的，因此您应该能够使用系统 Qt5 而不是提供的版本。您可以通过删除 5.6 库文件来实现这一点，或者如果这些是该目录中唯一重要的库文件，那么您可以完全省略$LD_LIBRARY_PATH。