We're trying to use the VERSION file, to both generate the app_version.h file (so that the application can know its own version numbers), and to update the version which gets put into the MCUBoot headers during signing. (And which our firmware handling system also uses to know the version of a .bin file)
If one does a pristine build, both app_version.h and the MCUBoot signing process correctly incorporate the information from VERSION
But if one does a normal "west build", then app_version.h is updated, but the although the MCUBoot signing does happen, it uses outdated VERSION information - because CONFIG_MCUBOOT_IMGTOOL_SIGN_VERSION has not been updated.
This obviously leaves the application thinking it is one version number but the bootloader thinking it is another.
I am not sure if improving incremental build is really one of the aims of the project, but it would probably be better for it to either update both these versions, or to update neither.
