check_compliance.py: Improve error reporting for Git commands

Similar improvements to
zephyrproject-rtos/zephyr#21577. No custom
potentially-missing working directory is used here, but always including
the exception message still feels more robust.

Use err() instead of sys.exit() in git(), and have it include the
command name, which is helpful in logs.

Signed-off-by: Ulf Magnusson <[email protected]>

Author: ulfalizer

scripts/check_compliance.py

@@ -40,19 +40,22 @@ def git(*args):
     try:
         git_process = subprocess.Popen(
             git_cmd, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
-    except FileNotFoundError:
-        sys.exit("git executable not found (when running '{}'). Check that "
-                 "it's in listed in the PATH environment variable"
-                 .format(git_cmd_s))
     except OSError as e:
-        sys.exit("failed to run '{}': {}".format(git_cmd_s, e))
+        err("failed to run '{}': {}".format(git_cmd_s, e))
 
     stdout, stderr = git_process.communicate()
+    stdout = stdout.decode("utf-8")
+    stderr = stderr.decode("utf-8")
     if git_process.returncode or stderr:
-        sys.exit("failed to run '{}': {}".format(
-            git_cmd_s, stdout.decode("utf-8") + stderr.decode("utf-8")))
+        err("""\
+'{}' exited with status {} (note: output on stderr also counts as a failure).
 
-    return stdout.decode("utf-8").rstrip()
+==stdout==
+{}
+==stderr==
+{}""".format(git_cmd_s, git_process.returncode, stdout, stderr))
+
+    return stdout.rstrip()
 
 
 # This ends up as None when we're not running in a Zephyr tree
@@ -1272,7 +1275,10 @@ def main():
 
 
 def err(msg):
-    sys.exit("error: " + msg)
+    cmd = sys.argv[0]  # Empty if missing
+    if cmd:
+        cmd += ": "
+    sys.exit(cmd + "error: " + msg)
 
 
 if __name__ == "__main__":