inside qmake.exe folder
qmake.exe $C:/Qt/5.15.2/android/bin/qmake.exe D:\models\QTDev\qgroundcontrol\qgroundcontrol.pro -spec android-clang "CONFIG+=debug" "CONFIG+=qml_debug" ANDROID_ABIS="arm64-v8a"
in qgc folder and entered to build
qmake.exe ../qgroundcontrol.pro -spec android-clang "CONFIG+=debug" "CONFIG+=qml_debug" ANDROID_ABIS="arm64-v8a"
f
C:\Users\ubayd\AppData\Local\Android\qgroundcontrol\build>"C:\Users\ubayd\AppData\Local\Android\Sdk\ndk\21.3.6528147\prebuilt\windows-x86_64\bin\make.exe" qmake_all
d
C:\Users\ubayd\AppData\Local\Android\qgroundcontrol\build>"C:\Users\ubayd\AppData\Local\Android\Sdk\ndk\21.3.6528147\prebuilt\windows-x86_64\bin\make.exe" -j8
d folder
D:\models\QTDev\qgroundcontrol\build>"D:\Programs\Android\Sdk\ndk\21.3.6528147\prebuilt\windows-x86_64\bin\make.exe" -j8
go to /libs/libevents/libevents/ and run git submodule init && git submodule update, that will pull the latest libevents that has the file you are missing
git submodule init && git submodule update