ID 368680 - Obsolete KnobTypes should not be accessible through Python calls

Follow
  1. The Foundry SANDBOX
  2. Bug Tracker
  3. Nuke

Problem summary
Within Nuke's Knob_Types, we have an obsolete knob named Obsolete_Font_Knob.

Users have discovered and faced issues attempting to use the obsolete knob through creating the Knob_Type with Python.
The User font knob currently has no functionality to be serialised, which is causing the exceptions.

Unsupported user Knob types, such as the above, shouldn't allow users to create them Pythonically and throw an exception stating that it is not available.

Customer reported version
nuke.11.2v1

Customer reported platform
centos7

Steps to reproduce

1) Open Nuke

2) Copy/Paste the following into the Script Editor:

dot = nuke.nodes.Dot()
font_knob = nuke.Font_Knob("font_file")
font_knob.setLabel("Font")
dot.addKnob(font_knob)
3)  Execute the Snippet, this should create a Dot node with an Obsolete_Font_knob

4)  Save and reopen the script.

Result: Reopening the script will throw the following Error:

"Obsolete_knob font_file call is wrong, probably a missing NULL for script argument"


This is due to the obsolete knob containing no Seriealization.


Workaround
As the KnobType is Obsolete/Unsupported, avoid use of said knob.

Our current supported knobs can be accessed through the following article:
Nuke Developers Guide - Knobs and Handles - KnobTypes

Reproduced by support

This bug has been reproduced in:
Nuke11.2v4 - Windows 7 - Mac10.13 - CentOS6.9
Nuke11.2v1 - Windows 7
Nuke11.1v4 - Windows 7 - Mac10.13 - CentOS6.9
Nuke11.1v1 - Windows 7
Nuke11.0v4 - Windows 7
Nuke11.0v1 - Windows 7
Nuke10.5v7 - Windows 7
Nuke10.5v1 - Windows 7
Nuke10.0v6 - Windows 7
Nuke10.0v1 - Windows 7
Nuke9.0v9 - Windows 7
Nuke9.0v1 - Windows 7
Nuke8.0v7 - Windows 7
Nuke7.0v10 - Windows 7 - Mac10.13 - CentOS6.9

Earliest version tested
- This issue appears to be in all versions of the product

Expected behaviour
Obsolete KnobTypes should not be accessible through Python calls.


Actual behaviour
Due to obsolete knobs being accessible, users are experiencing issues attempting to use said KnobTypes.

    We're sorry to hear that

    Please tell us why