AttributeError: 'NoneType' object has no attribute 'groups' on 2-axis machines

[leone2805]

Describe the bug
The plugin crashes when receiving status reports from a 2-axis GRBL machine (e.g., Laser engraver). The regex in _bgs.py expects at least 3 coordinates (X, Y, Z), but since my machine only reports X and Y, the regex match fails and returns None, causing an AttributeError.

Traceback

2026-05-02 15:00:22,385 - octoprint.util.comm - ERROR - Error while processing hook bettergrblsupport:
Traceback (most recent call last):
  File "/octoprint/plugins/lib/python3.10/site-packages/octoprint/util/comm.py", line 4218, in _readline
    ret = hook(self, ret)
  File "/octoprint/plugins/lib/python3.10/site-packages/octoprint/util/__init__.py", line 1692, in wrapper
    return f(*args, **kwargs)
  File "/octoprint/plugins/lib/python3.10/site-packages/octoprint_bettergrblsupport/__init__.py", line 1112, in hook_gcode_received
    return _bgs.process_grbl_status_msg(self, line)
  File "/octoprint/plugins/lib/python3.10/site-packages/octoprint_bettergrblsupport/_bgs.py", line 598, in process_grbl_status_msg
    response = 'X:{1} Y:{2} Z:{3} E:0 {original}'.format(*match.groups(), original=msg)
AttributeError: 'NoneType' object has no attribute 'groups'

Serial Logs
Here is the raw data being sent by my controller:

Send: ?
Recv: <Idle|MPos:0.000,0.000|FS:0,0|WCO:0.000,0.000>
Recv: ok

Proposed Fix
The regex in process_grbl_status_msg should be updated to make the Z-axis (and additional axes) optional, and the formatting logic should check if match is not None before accessing .groups().

def process_grbl_status_msg(_plugin, msg):
    # This regex makes the 3rd, 4th, 5th, and 6th axes optional
    match = re.search(r'<(-?[^,]+)[,|][WM]Pos:(-?[\d\.]+),(-?[\d\.]+)(?:,(-?[\d\.]+))?(?:,(-?[\d\.]+))?(?:,(-?[\d\.]+))?', msg)
    groups = match.groups()
    # Fallback to 0.000 if Z (groups[3]) is missing
    x = groups[1]
    y = groups[2]
    z = groups[3] if groups[3] is not None else "0.000"
    response = 'X:{0} Y:{1} Z:{2} E:0 {original}'.format(x, y, z, original=msg)
   ....

Version
Better Grbl Support (2.3.2)