Procedures to reproduce this issue are as follows.
1. Unzipping caf_flash.zip to C:\ncs\v2.5.2\nrf\samples folder.
2. cd C:\ncs\v2.5.2\nrf\samples\caf_flash
3. west build -b nrf5340dk_nrf5340_cpuapp
The following are log messages of west build.
C:\ncs\v2.5.2\nrf\samples\caf_flash>west build -b nrf5340dk_nrf5340_cpuapp -- west build: generating a build system Loading Zephyr default modules (Zephyr base). -- Application: C:/ncs/v2.5.2/nrf/samples/caf_flash -- CMake version: 3.20.5 -- Using NCS Toolchain 2.5.20231017.848171396279 for building. (C:/ncs/toolchains/c57af46cb7/cmake) ... CMake Warning at C:/ncs/v2.5.2/nrf/cmake/partition_manager.cmake:79 (message): --------------------------------------------------------------------- --- WARNING: Using a bootloader without pm_static.yml. --- --- There are cases where a deployed product can consist of --- --- multiple images, and only a subset of these images can be --- --- upgraded through a firmware update mechanism. In such cases, --- --- the upgradable images must have partitions that are static --- --- and are matching the partition map used by the bootloader --- --- programmed onto the device. --- ---------------------------------------------------------------------