alice-teacher AssertionError when dropping a procedure with a parameter

[Vanderhyde, James]

I discovered a bug in Alice 3.8 when demoing something in class yesterday. Some students experienced it in class as well. It happens on both Mac and Windows.

The bug occurs when creating a scene procedure with a parameter. If the procedure is already in use, it has to be updated, OK. If you try to drag another invocation of the procedure, the drop sometimes generates an AssertionError. The Queen pops up. The drag and drop action is interrupted. I tell students to save and relaunch Alice. Nothing bad seems to happen after.

Here are the steps to reproduce the error:
1. Launch Alice. Create a new scene.
2. Add a scene procedure.
3. Switch back to myFirstMethod and call the new procedure.
4. Switch back to the new procedure and add a parameter. Tick the box "I understand I need to update the invocations to this procedure."
5. Switch back to myFirstMethod.
6. Fix the invocation (or not, it doesn't matter)
7. Drag a new invocation of the procedure, and drop it _above_ the existing procedure invocation.
This generates an "Assertion Error."

I have been using this same process for teaching parameters for years in Alice 3 without encountering this issue, so I think it is new to version 3.8. I filed the bug report within the Alice environment.

James
—
James Vanderhyde
Associate Professor
Computer Science
Saint Xavier University
3700 W. 103rd St.
Chicago, IL 60655
773-298-3454
vanderhyde at sxu.edu<mailto:vanderhyde at sxu.edu>
sxu.edu<http://sxu.edu>

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.andrew.cmu.edu/pipermail/alice-teachers/attachments/20240125/2baac6b9/attachment.html>