When using a build folder format with build.dir-fmt that includes any
parameters that need resolving, the west runners cannot find the folder
since the required information (board, source dir or app) is not
available.
Add a very simple heuristic to support the case where a build folder
starts with a hardcoded prefix (for example 'build/') and a single build
is present under that prefix.
The heuristic is gated behind a new configuration option:
build.guess-dir
Signed-off-by: Carles Cufi <carles.cufi@nordicsemi.no>
41f1f648f6
