ID 422859 - Nuke crashes when exporting Transform (stabilize) and Transform (match-move) Transform nodes from a Tracker node

Problem summary
Nuke crashes when exporting Transform (stabilize) and Transform (match-move) Transform nodes from a Tracker4 node

All other exports don't crash Nuke

Customer reported version
nuke.12.0v4

Customer reported platform
centos8

Steps to reproduce

1) Open Nuke 12.0v4

2) Create a Tracker node

3) In the export options, select Transform (stabilize) or Transform (match-move), and press Export, Nuke crashes

Expected behaviour
For the expression linked transform 

Actual behaviour
Nuke Crashed 

Workaround
Create the Transform node and add the equivalent expressions into the knobs. This can be done manually, or by using the basic example code below:

Select the Tracker node, the run the below code to create a Transform (stabilize):

n = nuke.selectedNode()

if n.Class() == "Tracker4":
    t = nuke.nodes.Transform()
    t.setName("Transform_Stabilize1")
    t["translate"].setExpression("(!invert) ? Tracker1.translate.x : -Tracker1.translate.x".replace("Tracker1", n.name()), 0)
    t["translate"].setExpression("(!invert) ? Tracker1.translate.y : -Tracker1.translate.y".replace("Tracker1", n.name()), 1)
    t["rotate"].setExpression("(!invert) ? Tracker1.rotate : -Tracker1.rotate".replace("Tracker1", n.name()))
    t["scale"].setSingleValue(False)
    t["scale"].setExpression("(!invert) ? Tracker1.scale.w : 1/Tracker1.scale.w".replace("Tracker1", n.name()), 0)
    t["scale"].setExpression("(!invert) ? Tracker1.scale.h : 1/Tracker1.scale.h".replace("Tracker1", n.name()), 1)
    t["center"].setExpression("(!invert) ? Tracker1.center.x : Tracker1.center.x + Tracker1.translate.x".replace("Tracker1", n.name()), 0)
    t["center"].setExpression("(!invert) ? Tracker1.center.y : Tracker1.center.y + Tracker1.translate.y".replace("Tracker1", n.name()), 1)
    t["filter"].setExpression("Tracker1.filter".replace("Tracker1", n.name()))
    t.addKnob(nuke.Enumeration_Knob("transform", "transform", ["stabilize", "match-move"]))
    t.addKnob(nuke.Enumeration_Knob("src_transform", "src transform", ["none", "stabilize", "stabilize 1-pt", "match-move", "match-move 1-pt", "remove jitter"]))
    t["src_transform"].setExpression("Tracker1.transform".replace("Tracker1", n.name()))
    t.addKnob(nuke.Boolean_Knob("invert", "invert"))
    t["invert"].setFlag(nuke.ENDLINE)
    t["invert"].setExpression("[python -execlocal srcTransformKnob\\ =\\ nuke.thisNode()\\['src\\_transform'\\]\\nsrcTransformName\\ =\\ srcTransformKnob.enumName(int(srcTransformKnob.getValue()))\\ndestTransform\\ =\\ nuke.thisNode()\\['transform'\\].getValue()\\nsrcTransformIsStabilize\\ =\\ (srcTransformName.find('stabilize')==0\\ or\\ srcTransformName.find('remove\\ jitter')==0)\\ninvertDueToDestStabilize\\ =\\ (destTransform\\ ==\\ 0\\ and\\ not\\ srcTransformIsStabilize)\\ninvertDueToSrcStabilize\\ =\\ (destTransform\\ ==\\ 1\\ and\\ srcTransformIsStabilize)\\nret\\ =\\ (invertDueToDestStabilize\\ or\\ invertDueToSrcStabilize)]")

Select the Tracker node, the run the below code to create a Transform (match-move):

n = nuke.selectedNode()

if n.Class() == "Tracker4":
    t = nuke.nodes.Transform()
    t.setName("Transform_MatchMove1")
    t["translate"].setExpression("(!invert) ? Tracker1.translate.x : -Tracker1.translate.x".replace("Tracker1", n.name()), 0)
    t["translate"].setExpression("(!invert) ? Tracker1.translate.y : -Tracker1.translate.y".replace("Tracker1", n.name()), 1)
    t["rotate"].setExpression("(!invert) ? Tracker1.rotate : -Tracker1.rotate".replace("Tracker1", n.name()))
    t["scale"].setSingleValue(False)
    t["scale"].setExpression("(!invert) ? Tracker1.scale.w : 1/Tracker1.scale.w".replace("Tracker1", n.name()), 0)
    t["scale"].setExpression("(!invert) ? Tracker1.scale.h : 1/Tracker1.scale.h".replace("Tracker1", n.name()), 1)
    t["center"].setExpression("(!invert) ? Tracker1.center.x : Tracker1.center.x + Tracker1.translate.x".replace("Tracker1", n.name()), 0)
    t["center"].setExpression("(!invert) ? Tracker1.center.y : Tracker1.center.y + Tracker1.translate.y".replace("Tracker1", n.name()), 1)
    t["filter"].setExpression("Tracker1.filter".replace("Tracker1", n.name()))
    t.addKnob(nuke.Enumeration_Knob("transform", "transform", ["stabilize", "match-move"]))
    t["transform"].setValue("match-move")
    t.addKnob(nuke.Enumeration_Knob("src_transform", "src transform", ["none", "stabilize", "stabilize 1-pt", "match-move", "match-move 1-pt", "remove jitter"]))
    t["src_transform"].setExpression("Tracker1.transform".replace("Tracker1", n.name()))
    t.addKnob(nuke.Boolean_Knob("invert", "invert"))
    t["invert"].setFlag(nuke.ENDLINE)
    t["invert"].setExpression("[python -execlocal srcTransformKnob\\ =\\ nuke.thisNode()\\['src\\_transform'\\]\\nsrcTransformName\\ =\\ srcTransformKnob.enumName(int(srcTransformKnob.getValue()))\\ndestTransform\\ =\\ nuke.thisNode()\\['transform'\\].getValue()\\nsrcTransformIsStabilize\\ =\\ (srcTransformName.find('stabilize')==0\\ or\\ srcTransformName.find('remove\\ jitter')==0)\\ninvertDueToDestStabilize\\ =\\ (destTransform\\ ==\\ 0\\ and\\ not\\ srcTransformIsStabilize)\\ninvertDueToSrcStabilize\\ =\\ (destTransform\\ ==\\ 1\\ and\\ srcTransformIsStabilize)\\nret\\ =\\ (invertDueToDestStabilize\\ or\\ invertDueToSrcStabilize)]")

Reproduced by support
This bug has been reproduced in:

Nuke 12.0v4 - Windows 10, CentOS 7.7, macOS 10.13 - regression

Unable to reproduce bug in:
Nuke 12.0v3 - Windows 10, CentOS 7.7, macOS 10.13

Earliest version tested
Nuke 12.0v3 - This issue doesn't appear in this version and has regressed