Use 'fn' for a function

misc/vinyl_cutter/README.md

@@ -422,4 +422,69 @@ Warning: Ignoring XDG_SESSION_TYPE=wayland on Gnome. Use QT_QPA_PLATFORM=wayland
 
 ![inkcut in action](start_inkcut.png)
 
+Starting fails: Inkcut cannot open the port
 
+![Inkcut could not open the port](inkcut_could_not_open_port.png)
+
+```
+sudo usermod -a -G dialout "$USER"
+```
+
+
+Error at https://inkcut.org/t/could-not-open-port-devttyacm0-errno-13-permission-denied-devttyacm0/124/ :
+
+> Resolved
+> after running
+> sudo usermod -a -G dialout "$USER"
+> Logging out, and in, didn't do it, though a cold boot did.
+
+Then next error:
+
+
+```
+2024-08-22 21:11:59,948 | CRITICAL | inkcut | Traceback (most recent call last):
+  File "/home/richel/inkcut_venv/lib/python3.12/site-packages/twisted/internet/defer.py", line 2287, in unwindGenerator
+    return _cancellableInlineCallbacks(gen)
+  File "/home/richel/inkcut_venv/lib/python3.12/site-packages/twisted/internet/defer.py", line 2197, in _cancellableInlineCallbacks
+    _inlineCallbacks(None, gen, status, _copy_context())
+  File "/home/richel/inkcut_venv/lib/python3.12/site-packages/twisted/internet/defer.py", line 2014, in _inlineCallbacks
+    result = context.run(gen.send, result)
+  File "/home/richel/inkcut_venv/lib/python3.12/site-packages/inkcut/device/plugin.py", line 576, in connect
+    yield defer.maybeDeferred(self.connection.connect)
+--- <exception caught here> ---
+  File "/home/richel/inkcut_venv/lib/python3.12/site-packages/inkcut/device/plugin.py", line 749, in submit
+    yield defer.maybeDeferred(self.connect)
+  File "/home/richel/inkcut_venv/lib/python3.12/site-packages/inkcut/device/plugin.py", line 576, in connect
+    yield defer.maybeDeferred(self.connection.connect)
+  File "/home/richel/inkcut_venv/lib/python3.12/site-packages/twisted/internet/defer.py", line 212, in maybeDeferred
+    result = f(*args, **kwargs)
+  File "/home/richel/inkcut_venv/lib/python3.12/site-packages/inkcut/device/transports/serialport/plugin.py", line 86, in connect
+    self.connection = SerialPort(
+  File "/home/richel/inkcut_venv/lib/python3.12/site-packages/twisted/internet/_posixserialport.py", line 39, in __init__
+    self._serial = self._serialFactory(
+  File "/home/richel/inkcut_venv/lib/python3.12/site-packages/serial/serialutil.py", line 244, in __init__
+    self.open()
+  File "/home/richel/inkcut_venv/lib/python3.12/site-packages/serial/serialposix.py", line 332, in open
+    self._reconfigure_port(force_update=True)
+  File "/home/richel/inkcut_venv/lib/python3.12/site-packages/serial/serialposix.py", line 401, in _reconfigure_port
+    raise SerialException("Could not configure port: {}".format(msg))
+serial.serialutil.SerialException: Could not configure port: (5, 'Input/output error')
+```
+
+![inkcut could not configure port](inkcut_could_not_configure_port.png)
+
+Use a parallel port instead, from the blue USB:
+
+![](inkcut_use_parallel_port.png)
+
+Permission denied on that parallel port:
+
+
+![](inkcut_permission_denied_parallel_port.png)
+
+
+I guess, from https://askubuntu.com/questions/73687/what-is-the-correct-way-to-change-permissions-of-the-printer-in-dev-usb-lp0#73694 :
+
+```
+sudo usermod -a -G lpadmin "$USER"
+```