[nrf noup] scripts: west: build: Use sysbuild by default if in NCS dir

Uses sysbuild by default when building an application which resides in
an allowed NCS-based directory when the sysbuild config key is not
set. Do not use sysbuild if the mps2 board is being used to avoid
problems with CI testing.

Signed-off-by: Jamie McCrae <[email protected]>
(cherry picked from commit 5bbb2c8)

Author: nordicjm

scripts/west_commands/build.py

@@ -642,7 +642,12 @@ def _run_cmake(self, board, origin, cmake_opts):
         if user_args:
             cmake_opts.extend(shlex.split(user_args))
 
-        config_sysbuild = config_getboolean('sysbuild', False)
+        config_sysbuild = config_getboolean('sysbuild', None)
+
+        if config_sysbuild is None:
+            # If no option is set, then enable sysbuild globally
+            config_sysbuild = True
+
         if self.args.sysbuild or (config_sysbuild and not self.args.no_sysbuild):
             cmake_opts.extend([f'-S{SYSBUILD_PROJ_DIR}',
                                f'-DAPP_DIR:PATH={self.source_dir}'])