Error when removing simple equations for a simple model

[Leonardo Laguna]

Some time ago I reported a an error (ticket #2095) that seems to be fixed but Is still get the error in the latest build. To reproduce, use the following model:

  model ExtractionSetSTest
    Real x1(uncertain=Uncertainty.refine);
    Real x2(uncertain=Uncertainty.refine);
    Real x3(uncertain=Uncertainty.refine);
    Real y1;
    Real y2;
    Real y3;
  equation
    x1+x2 = 0;
    x1-x2 = 0;
    y1 = x2+2*x3;
    x3-y1+y2=x2;
    y2+y3=0;
    y2-2*y3=3;
  end ExtractionSetSTest;

ans try to build it. You should get the error message:

- BackendVariable.vararrayNth 1 has NONE!!!
Error processing file: ExtractionSetSTest.mo
Error: Internal error pre-optimization module removeSimpleEquations failed.
Error: Internal error Transformation Module PFPlusExt index Reduction Method Pantelides failed!

However the model is correct.

[Jens Frenkel]

x1=-x2 -> x1:=-x2 -> x2:=0
x1=x2 -> x1=-x1 -> x1:=0
y2=-y3 -> y2:=1
-y3-2*y3=3 -> y3:=-1
x3-y1+1=x2; -> x3-y1+1=0 -> x3:=1
y1 = x2+2*x3; -> y1 := 2*x3 -> y1:=2

[Leonardo Laguna]

I forgot to mention. This model is part of the redundancy tests of models with uncertainties. That's why it's written that way.

[Adrian Pop]

Leonardo, what would the compiler should do in this case?
We should not remove variables having uncertain attributes and the equations they are involved in?

[Leonardo Laguna]

I think in this case the equations should just pass since they are going to be handled by the uncertainties algorithm. However I think that for any regular simulation the exceptions applied for a model with uncertainties should not apply (e.g. not removing the variables with uncertain annotation).
Maybe we should disable all the uncertainties specific behavior with a flag that is enabled when calling the uncertainties code.

[Martin Sjölund]

This ticket was not closed for 1.9.1, which has now been released. It was batch modified for milestone 1.9.2 (but maybe an empty milestone was more appropriate; feel free to change it).

[Martin Sjölund]

Milestone changed to 1.9.3 since 1.9.2 was released.

[Martin Sjölund]

Moved to new milestone 1.9.4

[Martin Sjölund]

Milestone pushed to 1.9.5

[Martin Sjölund]

Milestone renamed

[Martin Sjölund]

Ticket retargeted after milestone closed

[Martin Sjölund]

Milestone moved to 1.12.0 due to 1.11.0 already being released.

[Francesco Casella]

The milestone of this ticket has been reassigned to "Future".

If you think the issue is still valid and relevant for you, please select milestone 1.13.0 for back-end, code generation and run-time issues, or 2.0.0 for front-end issues.

If you are aware that the problem is no longer present, please select the milestone corresponding to the version of OMC you used to check that, and set the status to "worksforme".

In both cases, a short informative comment would be welcome.