Cross compiling Qt6 for raspberry pi with eglfs option

glamis

I'm trying to compile Qt6 for Raspberry Pi Zero W with EGLFS option enabled. Previously I have successfully compiled and deployed QT5.15 on the same platform with EGLFS so I'm reusing the same developpement environment (same sysroot and cross compiler). However after configuration I cannot get the EGLFS Raspberry Pi option to be enabled i.e. the output is:

 eglfs .................................. yes
  EGLFS details:
    EGLFS OpenWFD ........................ no
    EGLFS i.Mx6 .......................... no
    EGLFS i.Mx6 Wayland .................. no
    EGLFS RCAR ........................... no
    EGLFS EGLDevice ...................... no
    EGLFS GBM ............................ yes
    EGLFS VSP2 ........................... no
    EGLFS Mali ........................... no
    eglfs_brcm ........................... yes
    EGLFS X11 ............................ no

However in CMakeError.log I see :

Test HAVE_egl_brcm failed with the following output:
...
undefined reference to `vc_dispmanx_display_open

My cmake configuration options are :

    cmake -G"Unix Makefiles" -DCMAKE_BUILD_TYPE=Release -DINPUT_opengl=es2 -DQT_FEATURE_opengles3=ON -DQT_FEATURE_eglfs=ON -DQT_FEATURE_eglfs_brcm=ON -DQT_QPA_DEFAULT_PLATFORM=eglfs\
    -DQT_BUILD_EXAMPLES=OFF -DQT_BUILD_TESTS=OFF \
    -DQT_HOST_PATH=$QT_HOST_PATH                          \
    -DCMAKE_STAGING_PREFIX=$SYSROOT_PATH/$QT_INSTALL_PATH_ON_PI                  \
    -DCMAKE_INSTALL_PREFIX=/$QT_INSTALL_PATH_ON_PI                 \
    -DCMAKE_TOOLCHAIN_FILE=$TOOLCHAIN_FILE  \
    $QT_SRC_PATH/qtbase

I know that my CMAKE_TOOLCHAIN_FILE file works as I have used it previously for other projects.
Do you know what I'm doing wrong ?