Circular dependency bug

[mroek]

I have a design that I have now done twice (I restarted due to getting a Circular dependency that I could not resolve).

For the first design, I was more or less finished with it, but I was getting errors when I tried to use a surface model to split a solid body. The error was that there was no intersection, which there clearly was. So I did a "Compute All" to see if that would do anything, and it broke my model with a long chain of "Circular dependency" errors. At that point I gave up and just started from scratch, this time doing regular "Compute All" to avoid getting into the same pickle.

However, suddenly I'm back to getting that dreaded "Circular dependency", but this time I know exactly which operation causes it, and there is no way it is a real "Circular dependency", as the feature that breaks it is from a clean sketch that has no projections or dependencies on anything.

I don't want to share the design publicly, but I can share it with specific people (and Autodesk employees). However, here's a picture:

After completing this surface extrude, a "Compute All" will throw cicular dependency errors, even if that sketch is not projecting anything, and is drawn on a origin plane. It doesn't matter what the sketch geometry is, a single straight line causes the same issue.

I am suspecting that this is due to a derive feature which the design is based on, but in this case I tried breaking the link immediately after inserting the derive, so the timeline starts with a base feature that contains a single surface model, which I am then building on in this design.

I have no clue how to get past this. Extremely annoying.

@jeff_straterMaybe you can take a look at this? Reproducing this is as easy as trying to do that extrude and then "Compute all".

[mroek]

Actually, creating a new sketch (with any kind of geometry) on any plane and doing a surface extrude of said sketch will produce the "Circular dependency" error. Creating the sketch does not cause the issue, it is only after doing a surface extrude it all goes wrong.

[jeff_strater]

Thanks, @mroek - yes, I'd be interested in the design.  My guess, though, is that the cycle is already there, and doing an Extrude, or a Sketch merely triggers the compute, which detects an already-present cycle.

What is more important is to try to figure out when/how the cycle got introduced.  What would be helpful here is to go back through old versions - open older versions, do Compute All, until you find one that does not have the cycle, then look at the difference between that version and the next, and see if we can figure out what the difference is.  It's a lot to ask, but we'd really appreciate the ability to find the operation sequence that causes this.  It's hard to figure out after the cycle exists.  So, if you have any clues that can help, it'd be very helpful to us.  We have seen a few of these recently, so we are keen to find the underlying cause.  Thanks!

[mroek]

@jeff_strater:

Thanks for getting back to me. I hear what you say, but the design that I did the derive from, did not have the circular dependency. I can "Compute all" as much as I want, but no issues pop up.

My workaround was actually to just do a "Save as" on the source design, and then use that as the base for what I wanted to make. I'll send you an email with some actual data.