Building QT 6 for Android on Windows from sources

[Dmitriano]

Tried to build QT for Android on Windows according to this: https://doc-snapshots.qt.io/qt6-dev/android-building.html

But did not figure out

1. what is the difference between "-prefix <\path\to\install>" and "-qt-host-path <path_to_host_qt_installation>" "configure.bat" parameters
2. how to specify -DQT_NO_EXCEPTIONS as "configure.bat" parameter

Tried the following:

set "MY_INSTALL_PATH=E:\Qt\Qt6.0.2\android"
set QT_HOST_PATH=%MY_INSTALL_PATH%

rem QT_NO_EXCEPTIONS disables "try { } catch (...) {}" surrounding the user code in qthread_unix.cpp
configure.bat -prefix %MY_INSTALL_PATH% -qt-host-path %MY_INSTALL_PATH% -DQT_NO_EXCEPTIONS=1 -release -force-debug-info -platform win32-g++ -opengl es2 -xplatform android-clang ^
  -android-ndk %ANDROID_NDK_PATH% -android-sdk %ANDROID_SDK_ROOT% -android-abis arm64-v8a -android-ndk-host windows-x86_64 ^
  -opensource -confirm-license -nomake tests -nomake examples

but got:

Configuring 'qtbase'
-- Android NDK detected: C://Users//D-Ef//AppData//Local//Android//Sdk/ndk-bundle
-- Android toolchain file detected
CMake Error at qtbase/cmake/QtSetup.cmake:173 (message):
  You need to set QT_HOST_PATH to cross compile Qt.
Call Stack (most recent call first):
  qtbase/cmake/QtBuildInternals/QtBuildInternalsConfig.cmake:173 (include)
  qtbase/cmake/QtBuildInternals/QtBuildInternalsConfig.cmake:271 (qt_build_internals_set_up_private_api)
  qtbase/CMakeLists.txt:57 (qt_build_repo_begin)

-- Configuring incomplete, errors occurred!

3. where should I set QT_HOST_PATH?
4. how to clean the configuration (after executing configure.bat with wrong parameters)?

[xtofl]

1.b https://www.qt.io/blog/qt-6-build-system seems to contain some information on this.

The QT_HOST_PATH is to be set by using the -qt-host-path switch.

To cross-build Qt, you need to point to an already existing native build of your host platform. This is called the host Qt.

[Dmitriano]

@xtofl yes, I see, but what is QT_HOST_PATH?

And why am I getting the error

You need to set QT_HOST_PATH to cross compile Qt

if I set it with -qt-host-path?

[Nick Bennett]

On Windows, the default path would be C:\Qt. (This is where the Qt Online Installer would install it)