Add fsync() call in atomic_writing

IPython/utils/io.py

@@ -260,7 +260,11 b" def atomic_writing(path, text=True, encoding='utf-8', **kwargs):"
         fileobj.close()
         os.remove(tmp_path)
         raise
-    else:
+
+    # Flush to disk
+    fileobj.flush()
+    os.fsync(fileobj.fileno())
+
         # Written successfully, now rename it
         fileobj.close()