Add error logging to scripts/print_exported_headers

ghstack-source-id: 5437831
ghstack-comment-id: 3225036431
Pull-Request: #13686

Author: swolchok

scripts/print_exported_headers.py

@@ -22,7 +22,11 @@
 
 def run(command: List[str]) -> str:
     """Run subprocess and return its output."""
-    result = subprocess.run(command, capture_output=True, check=True, cwd=BUCK_CWD)
+    try:
+        result = subprocess.run(command, capture_output=True, check=True, cwd=BUCK_CWD)
+    except subprocess.CalledProcessError as ex:
+        print(f"Subprocess failed. stdout: {ex.stdout}\nstderr: {ex.stderr}")
+        raise
     return result.stdout.decode()