scripts: west_commands: fix ZEPHYR_BASE env check

detect_version() used os.environ["ZEPHYR_BASE"],
which raises a KeyError when the variable is
absent, preventing the fallback path from running.
Switch to os.environ.get("ZEPHYR_BASE") and use
Path(__file__).resolve() for the fallback so the
path is absolute/canonical.

Signed-off-by: Paul Oberosler <[email protected]>

Author: paulober

scripts/west_commands/sdk.py

@@ -210,10 +210,11 @@ def detect_version(self, args):
         if args.version:
             version = args.version
         else:
-            if os.environ["ZEPHYR_BASE"]:
-                zephyr_base = Path(os.environ["ZEPHYR_BASE"])
+            zephyr_base_env = os.environ.get("ZEPHYR_BASE")
+            if zephyr_base_env:
+                zephyr_base = Path(zephyr_base_env)
             else:
-                zephyr_base = Path(__file__).parents[2]
+                zephyr_base = Path(__file__).resolve().parents[2]
 
             sdk_version_file = zephyr_base / "SDK_VERSION"