build on Windows: update to Qt6; warn that last full test was for release 1.19

hugo/content/installation/building/windows/index.md

@@ -5,7 +5,9 @@ weight = 10
 
 ## Build under Windows
 
-The  following instructions have been tested under Windows 10 Pro.
+The following instructions have been tested under Windows 10 Pro.
+Last full test from our side was for release 1.19.
+
 
 ### Prerequisites
 
@@ -20,14 +22,15 @@ Download Qt from from the official website [qt.io](https://qt.io)
 
 > Make sure to choose the open source version of Qt and download the online installer.
 
-Select Qt 5.15.2 (LTS) and open the sub tree.
-Only 'MSVC 2019 64-bit' component is needed.
+Select the latest Qt version with long-time support (LTS) and open the sub tree.
+Only the 'MSVC 2019 64-bit' component is needed.
 
-Make a symbolic link to the directory corresponding to the current Qt version; e.g., if Qt 5.15.2 is installed in `C:\Qt\5.15.2`, then in Windows `cmd` (with administrative rights) execute:
+Make a symbolic link to the directory corresponding to the current Qt version:
+if Qt 6.y.z installed in `C:\Qt\6.y.z`, then in Windows `cmd` (with administrative rights) execute:
 
 ```
-$ mklink /D "C:\Qt\current" "C:\Qt\5.15.2"
-$ mklink /D "C:\Qt\msvc" "C:\Qt\5.15.2\msvc2019_64"
+$ mklink /D "C:\Qt\current" "C:\Qt\6.y.z"
+$ mklink /D "C:\Qt\msvc" "C:\Qt\6.y.z\msvc2019_64"
 ```
 
 #### CMake
@@ -89,7 +92,7 @@ and paste the corresponding content from the ZIP files in those two folders.
 After those installations your `PATH` should contain
 
 ```
-C:\Qt\5.15.2\msvc2019_64\bin
+C:\Qt\6.y.z\msvc2019_64\bin
 C:\Program Files\Python39\Scripts\
 C:\Program Files\Python39\
 C:\opt\x64\include
@@ -100,7 +103,8 @@ C:\Program Files (x86)\NSIS
 
 ### Build
 
-With all prerequisites completed, you should be able to build and test BornAgain in a PowerShell. In there, execute
+With all prerequisites completed, you should be able to build and test BornAgain in a PowerShell.
+In there, execute
 
 ```
 $OPTLIBS = "C:/opt/x64"
@@ -113,7 +117,7 @@ $BUILD_DIR = "build"
 mkdir -Force "$BUILD_DIR"
 cd "$BUILD_DIR"
 
-cmake -G "Visual Studio 17 2022" -A x64 -T host=x64 -DLIB_MAN=OFF -DQTDIR="$QTDIR" -DQt5_DIR="$QTCMake_DIR/Qt5" -DQt5Test_DIR="$QTCMake_DIR/Qt5Test" -DFFTW3_INCLUDE_DIR="$FFTW3_INCLUDE_DIR" -DFFTW3_LIBRARY="$FFTW3_LIB" -DCMAKE_INCLUDE_PATH="$OPTLIBS/include" -DCMAKE_LIBRARY_PATH="$OPTLIBS/lib" -DCMAKE_CXX_COMPILER_LAUNCHER=ccache -DCMAKE_C_COMPILER="cl.exe" -DCMAKE_CXX_COMPILER="cl.exe" -B. ..
+cmake -G "Visual Studio 17 2022" -A x64 -T host=x64 -DLIB_MAN=OFF -DQTDIR="$QTDIR" -DQt6_DIR="$QTCMake_DIR/Qt6" -DQt6Test_DIR="$QTCMake_DIR/Qt6Test" -DFFTW3_INCLUDE_DIR="$FFTW3_INCLUDE_DIR" -DFFTW3_LIBRARY="$FFTW3_LIB" -DCMAKE_INCLUDE_PATH="$OPTLIBS/include" -DCMAKE_LIBRARY_PATH="$OPTLIBS/lib" -DCMAKE_CXX_COMPILER_LAUNCHER=ccache -DCMAKE_C_COMPILER="cl.exe" -DCMAKE_CXX_COMPILER="cl.exe" -B. ..
 
 cmake --build . --config Release
 
@@ -142,7 +146,7 @@ cd "%BUILD_DIR%"
 
 cmake --version
 
-cmake -G "Ninja" -DCMAKE_BUILD_TYPE=Release -DQTDIR="%QTDIR%" -DQt5_DIR="%QTCMake_DIR%/Qt5" -DQt5Test_DIR="%QTCMake_DIR%/Qt5Test" -DFFTW3_INCLUDE_DIR="%FFTW3_INCLUDE_DIR%" -DFFTW3_LIBRARY="%FFTW3_LIB%" -DCMAKE_INCLUDE_PATH="%OPTLIBS%/include" -DCMAKE_LIBRARY_PATH="%OPTLIBS%/lib" -DLIB_MAN=OFF -DCMAKE_C_COMPILER="cl.exe" -DCMAKE_CXX_COMPILER="cl.exe" -B. ..
+cmake -G "Ninja" -DCMAKE_BUILD_TYPE=Release -DQTDIR="%QTDIR%" -DQt6_DIR="%QTCMake_DIR%/Qt6" -DQt6Test_DIR="%QTCMake_DIR%/Qt6Test" -DFFTW3_INCLUDE_DIR="%FFTW3_INCLUDE_DIR%" -DFFTW3_LIBRARY="%FFTW3_LIB%" -DCMAKE_INCLUDE_PATH="%OPTLIBS%/include" -DCMAKE_LIBRARY_PATH="%OPTLIBS%/lib" -DLIB_MAN=OFF -DCMAKE_C_COMPILER="cl.exe" -DCMAKE_CXX_COMPILER="cl.exe" -B. ..
 
 echo "## BUILD START:" %time%
 cmake --build . --config Release --parallel 8