Px4_fmu-v5_default build error on windows 10

Hi, I’m trying to build px4_fmu-v5 for the pixhawk 4, on windows 10.
i followed the instructions on Windows Development Environment | PX4 User Guide
installed the toolchain
run-console.bat
cloned my fork
then when i run “make px4_fmu-v5”, i ve this error
make px4_fmu-v5
– PX4 version: v1.12.0-beta5-244-g5b3c29237d
– PX4 config file: /cygdrive/d/D_Documents/ICL/AquaMAV/Autopilot/PX4/home/Firmware/boards/px4/fmu-v5/default.cmake
– PX4 config: px4_fmu-v5_default
– PX4 platform: nuttx
– cmake build type: MinSizeRel
– The CXX compiler identification is GNU 7.3.1
– The C compiler identification is GNU 7.3.1
– The ASM compiler identification is GNU
– Found assembler: /cygdrive/d/D_Documents/ICL/AquaMAV/Autopilot/PX4/toolchain/gcc-arm/bin/arm-none-eabi-gcc.exe
– Check for working CXX compiler: /cygdrive/d/D_Documents/ICL/AquaMAV/Autopilot/PX4/toolchain/gcc-arm/bin/arm-none-eabi-g++.exe
– Check for working CXX compiler: /cygdrive/d/D_Documents/ICL/AquaMAV/Autopilot/PX4/toolchain/gcc-arm/bin/arm-none-eabi-g++.exe – works
– Detecting CXX compiler ABI info
– Detecting CXX compiler ABI info - failed
– Detecting CXX compile features
– Detecting CXX compile features - failed
– Check for working C compiler: /cygdrive/d/D_Documents/ICL/AquaMAV/Autopilot/PX4/toolchain/gcc-arm/bin/arm-none-eabi-gcc.exe
– Check for working C compiler: /cygdrive/d/D_Documents/ICL/AquaMAV/Autopilot/PX4/toolchain/gcc-arm/bin/arm-none-eabi-gcc.exe – works
– Detecting C compiler ABI info
– Detecting C compiler ABI info - failed
– Detecting C compile features
– Detecting C compile features - failed
– Enabling double FP precision hardware instructions
– Found PythonInterp: /usr/bin/python3 (found suitable version “3.6.9”, minimum required is “3”)
– Build files have been written to: /cygdrive/d/D_Documents/ICL/AquaMAV/Autopilot/PX4/home/Firmware/build/px4_fmu-v5_default/external/Build/px4io_firmware
[29/1372] Performing build step for ‘px4io_firmware’
[0/244] git submodule platforms/nuttx/NuttX/nuttx
[7/244] git submodule platforms/nuttx/NuttX/apps
[19/244] Generating apps/libapps.a
FAILED: NuttX/apps/libapps.a
cd /cygdrive/d/D_Documents/ICL/AquaMAV/Autopilot/PX4/home/Firmware/build/px4_fmu-v5_default/external/Build/px4io_firmware/NuttX/apps && find /cygdrive/d/D_Documents/ICL/AquaMAV/Autopilot/PX4/home/Firmware/build/px4_fmu-v5_default/external/Build/px4io_firmware/NuttX/apps -name *.o -delete && make --quiet --no-print-directory TOPDIR="/cygdrive/d/D_Documents/ICL/AquaMAV/Autopilot/PX4/home/Firmware/build/px4_fmu-v5_default/external/Build/px4io_firmware/NuttX/nuttx" > nuttx_apps.log
Assembler messages:
Fatal error: can’t create dummy.cygdrive.d.D_Documents.ICL.AquaMAV.Autopilot.PX4.home.Firmware.build.px4_fmu-v5_default.external.Build.px4io_firmware.NuttX.apps.platform.o: No such file or directory
make[3]: *** [/cygdrive/d/D_Documents/ICL/AquaMAV/Autopilot/PX4/home/Firmware/build/px4_fmu-v5_default/external/Build/px4io_firmware/NuttX/apps/Application.mk:134: dummy.cygdrive.d.D_Documents.ICL.AquaMAV.Autopilot.PX4.home.Firmware.build.px4_fmu-v5_default.external.Build.px4io_firmware.NuttX.apps.platform.o] Error 1
make[2]: *** [Makefile:59: /cygdrive/d/D_Documents/ICL/AquaMAV/Autopilot/PX4/home/Firmware/build/px4_fmu-v5_default/external/Build/px4io_firmware/NuttX/apps/platform_all] Error 2
make[1]: *** [Makefile:53: all] Error 2
[22/244] Generating nuttx/fs/libfs.a
ninja: build stopped: interrupted by user.
[791/1372] Building CXX object src/drivers/magnetometer/isentek/ist8308/CMakeFiles/drivers__magnetometer__isentek__ist8308.dir/IST8308.cpp.obj
ninja: build stopped: interrupted by user.
make: *** [Makefile:228: px4_fmu-v5] Interrupt

px4_fmu-v4 and pix_sitl_default work.
Any idea what could be wrong there ?
Thanks,
Julien