zephyrproject\zephyr>$ west build -p auto -b teensy41 samples\basic\blinky
zephyrproject\zephyr>$ west flash <<Fail
zephyrproject\zephyr>$ cd build
zephyrproject\zephyr\build>$ west flash <<Fail
zephyrproject\zephyr\build>$ ninja flash <<Fail
Here is the error message show in windows10 cmd :
[0/1] Flashing teensy41
-- west flash: rebuilding
ninja: no work to do.
FATAL ERROR: either a pristine build is needed, or board teensy41 doesn't support west flash/debug (no ZEPHYR_RUNNERS_YAML in CMake cache)
FAILED: zephyr/cmake/flash/CMakeFiles/flash C:/Users/canic/Desktop/zephyrproject/zephyr/build/zephyr/cmake/flash/CMakeFiles/flash
cmd.exe /C "cd /D C:\Users\canic\Desktop\zephyrproject\zephyr\build && "C:\Program Files\CMake\bin\cmake.exe" -DTARGET=flash -DDEPENDENCIES="" -P C:/Users/canic/Desktop/zephyrproject/zephyr/cmake/flash/check_runner_dependencies.cmake && "C:\Program Files\CMake\bin\cmake.exe" -E env C:/Users/canic/AppData/Local/Programs/Python/Python39/python.exe -m west flash"
ninja: build stopped: subcommand failed.
I follow the Getting Started Guide, then
Is any step I do it wrong?