swap command fails with: "AttributeError: 'Namespace' object has no attribute 'maxsize'"

I tested the curtin 'swap' command this morning and hit an error:

Traceback (most recent call last):
  File "/root/curtin/curtin/commands/main.py", line 96, in main
    sys.exit(args.func(args))
  File "/root/curtin/curtin/commands/swap.py", line 53, in swap_main
    if args.maxsize is not None:
AttributeError: 'Namespace' object has no attribute 'maxsize'
'Namespace' object has no attribute 'maxsize'
Traceback (most recent call last):
  File "/root/curtin/curtin/commands/main.py", line 96, in main
    sys.exit(args.func(args))
  File "/root/curtin/curtin/commands/install.py", line 267, in cmd_install
    stage.run()
  File "/root/curtin/curtin/commands/install.py", line 104, in run
    util.subp(cmd, shell=shell, env=self.env)
  File "/root/curtin/curtin/util.py", line 68, in subp
    cmd=args)
ProcessExecutionError: Unexpected error while running command.
Command: curtin swap --size=auto
Exit code: 3
Reason: -
Stdout: ''
Stderr: ''