xlib is not linked

[mikhailnov]

DEBUG: g++ -O2 -fomit-frame-pointer -gdwarf-4 -Wstrict-aliasing=2 -pipe -Wformat -Werror=format-security -D_FORTIFY_SOURCE=2 -fPIC -fstack-protector-strong --param=ssp-buffer-size=4 -m64 -mtune=generic -Wl,-O2 -Wl,-O1 -O2 -fomit-frame-pointer -gdwarf-4 -Wstrict-aliasing=2 -pipe -Wformat -Werror=format-security -D_FORTIFY_SOURCE=2 -fPIC -fstack-protector-strong --param=ssp-buffer-size=4 -m64 -mtune=generic -fPIC -Wl,-O2 -Wl,--no-undefined -shared -o libqt5-ukui-platformtheme.so ukui-tabwidget-default-slide-animator-factory.o ukui-tabwidget-default-slide-animator.o ukui-scrollbar-default-interaction-animator.o animation-helper.o ukui-style-settings.o application-style-settings.o internal-style.o mps-style.o highlight-effect.o ukui-two-finger-slide-gesture.o ukui-two-finger-zoom-gesture.o message-box.o xatom-helper.o qt5-ukui-platform-theme.o main.o moc_ukui-tabwidget-default-slide-animator-factory.o moc_ukui-tabwidget-default-slide-animator.o moc_ukui-scrollbar-default-interaction-animator.o moc_animation-helper.o moc_ukui-style-settings.o moc_application-style-settings.o moc_internal-style.o moc_mps-style.o moc_highlight-effect.o moc_ukui-two-finger-slide-gesture.o moc_ukui-two-finger-zoom-gesture.o moc_xatom-helper.o moc_qt5-ukui-platform-theme.o  -lgsettings-qt /usr/lib64/libQt5Widgets.so /usr/lib64/libQt5ThemeSupport.a /usr/lib64/libQt5X11Extras.so /usr/lib64/libQt5Gui.so /usr/lib64/libQt5DBus.so /usr/lib64/libQt5Core.so -lGL -lpthread    
DEBUG: make[1]: Leaving directory '/builddir/build/BUILD/qt5-ukui-platformtheme-28e314d954edb58e28d1e4597584b8f68b6a67c8/qt5-ukui-platformtheme'
DEBUG: /usr/bin/x86_64-openmandriva-linux-gnu-ld: xatom-helper.o: in function `XAtomHelper::isUKUIDecorationWindow(int)':
DEBUG: /builddir/build/BUILD/qt5-ukui-platformtheme-28e314d954edb58e28d1e4597584b8f68b6a67c8/qt5-ukui-platformtheme/widget/xatom-helper.cpp:85: undefined reference to `XGetWindowProperty'
DEBUG: /usr/bin/x86_64-openmandriva-linux-gnu-ld: xatom-helper.o: in function `XAtomHelper::getWindowBorderRadius(int)':
DEBUG: /builddir/build/BUILD/qt5-ukui-platformtheme-28e314d954edb58e28d1e4597584b8f68b6a67c8/qt5-ukui-platformtheme/widget/xatom-helper.cpp:111: undefined reference to `XGetWindowProperty'
DEBUG: /usr/bin/x86_64-openmandriva-linux-gnu-ld: /builddir/build/BUILD/qt5-ukui-platformtheme-28e314d954edb58e28d1e4597584b8f68b6a67c8/qt5-ukui-platformtheme/widget/xatom-helper.cpp:124: undefined reference to `XFree'
DEBUG: /usr/bin/x86_64-openmandriva-linux-gnu-ld: xatom-helper.o: in function `XAtomHelper::setWindowBorderRadius(int, UnityCorners const&)':
DEBUG: /builddir/build/BUILD/qt5-ukui-platformtheme-28e314d954edb58e28d1e4597584b8f68b6a67c8/qt5-ukui-platformtheme/widget/xatom-helper.cpp:138: undefined reference to `XChangeProperty'
DEBUG: /usr/bin/x86_64-openmandriva-linux-gnu-ld: xatom-helper.o: in function `XAtomHelper::setWindowBorderRadius(int, int, int, int, int)':
DEBUG: /builddir/build/BUILD/qt5-ukui-platformtheme-28e314d954edb58e28d1e4597584b8f68b6a67c8/qt5-ukui-platformtheme/widget/xatom-helper.cpp:149: undefined reference to `XChangeProperty'
DEBUG: /usr/bin/x86_64-openmandriva-linux-gnu-ld: xatom-helper.o: in function `XAtomHelper::setUKUIDecoraiontHint(int, bool)':
DEBUG: /builddir/build/BUILD/qt5-ukui-platformtheme-28e314d954edb58e28d1e4597584b8f68b6a67c8/qt5-ukui-platformtheme/widget/xatom-helper.cpp:158: undefined reference to `XChangeProperty'
DEBUG: /usr/bin/x86_64-openmandriva-linux-gnu-ld: xatom-helper.o: in function `XAtomHelper::setWindowMotifHint(int, MotifWmHints const&)':
DEBUG: /builddir/build/BUILD/qt5-ukui-platformtheme-28e314d954edb58e28d1e4597584b8f68b6a67c8/qt5-ukui-platformtheme/widget/xatom-helper.cpp:166: undefined reference to `XChangeProperty'
DEBUG: /usr/bin/x86_64-openmandriva-linux-gnu-ld: xatom-helper.o: in function `XAtomHelper::getWindowMotifHint(int)':
DEBUG: /builddir/build/BUILD/qt5-ukui-platformtheme-28e314d954edb58e28d1e4597584b8f68b6a67c8/qt5-ukui-platformtheme/widget/xatom-helper.cpp:183: undefined reference to `XGetWindowProperty'
DEBUG: /usr/bin/x86_64-openmandriva-linux-gnu-ld: /builddir/build/BUILD/qt5-ukui-platformtheme-28e314d954edb58e28d1e4597584b8f68b6a67c8/qt5-ukui-platformtheme/widget/xatom-helper.cpp:191: undefined reference to `XFree'
DEBUG: /usr/bin/x86_64-openmandriva-linux-gnu-ld: xatom-helper.o: in function `XAtomHelper::XAtomHelper(QObject*)':
DEBUG: /builddir/build/BUILD/qt5-ukui-platformtheme-28e314d954edb58e28d1e4597584b8f68b6a67c8/qt5-ukui-platformtheme/widget/xatom-helper.cpp:201: undefined reference to `XInternAtom'
DEBUG: /usr/bin/x86_64-openmandriva-linux-gnu-ld: /builddir/build/BUILD/qt5-ukui-platformtheme-28e314d954edb58e28d1e4597584b8f68b6a67c8/qt5-ukui-platformtheme/widget/xatom-helper.cpp:202: undefined reference to `XInternAtom'
DEBUG: /usr/bin/x86_64-openmandriva-linux-gnu-ld: /builddir/build/BUILD/qt5-ukui-platformtheme-28e314d954edb58e28d1e4597584b8f68b6a67c8/qt5-ukui-platformtheme/widget/xatom-helper.cpp:203: undefined reference to `XInternAtom'
DEBUG: collect2: error: ld returned 1 exit status

$ readelf -a /usr/lib64/libX11.so | grep XGetWindowProperty
00000013e2e8  026700000007 R_X86_64_JUMP_SLO 0000000000029bc0 XGetWindowProperty + 0
   615: 0000000000029bc0   743 FUNC    GLOBAL DEFAULT   13 XGetWindowProperty

so, -lX11 must be added to LDFLAGS

[Mr-LeiChen]

Confirm whether libqt5x11extras5-dev is installed

[mikhailnov]

[user@rosa2019 ~]$ rpm -q --whatprovides 'pkgconfig(Qt5X11Extras)'
lib64qt5x11extras-devel-5.15.2-3.x86_64

yes, it is