PR# 19866 Program crashes after recompiling

Problem Report Summary
Submitter: mischa
Category: Compiler
Priority: Medium
Date: 2022/05/17
Class: Bug
Severity: Serious
Number: 19866
Release: 21.11; 19.05 has it too
Confidential: No
Status: Analyzed
Environment: win
Synopsis: Program crashes after recompiling

I have three small classes KLEENEAN_ANCESTOR, KLEENEAN_REF, and KLEENEAN, and a test class TEST_KLEENEAN (a copy is attached). When I compile for the first time, it runs just fine. But when I then make a minor change, such as adding an extra print("%N") statement at the beginning, and recompile, then when I try to run, the program crashes. Sometimes it even takes the whole EiffelStudio with it. When I delete the EIFGEN folder and recompile from scratch, then my program works again, as it did initially, and as expected. But I am forced to use "Project/Compile from scratch" (alternatively, quitting EiffelStudio and deleting the EIFGEN folder also works). So no "melting ice technology" for me with these classes (that is to say, when the ice melts, I sink through it and drown.) This happens consistently with these classes/this project.

With kind regards,
To Reproduce
- Compile & run TEST_KLEENEAN.
- Add an extra print statement at the beginning of the make feature
- Compile (F7) and run (F5)
- Observe it print 
Tests for KLEENEAN

- and then it crashes
Problem Report Interactions
From:mischa    Date:2022/05/18    Status: Analyzed    Download   
Dear Jocelyn,

Thank you for looking into it right away!
The 'Freeze' works very well :)
(I wouldn't mind if the 'severity' changed to 'non-critical'...
and I feel I'm hardly in a position to make any demands for the next release either, without a paid subscription...)

Warm regards,

From:jfiat_es    Date:2022/05/18    Status: Analyzed    Download   
Dear Mischa,

Thank you for your report.
Having a way to reproduce this issue is greatly appreciated.
We confirm we have been able to reproduce the issue.

For now, an alternative to the " recompile from scratch ", would be to "Freeze" the system.
We will inform you when we have updated information.

From:mischa    Date:2022/05/17    Download   
Attachments for problem report #19866

Attachment: exception_trace.log     Size:2091
Attachment: exception_trace_1.log     Size:3713
Attachment: kleenean.e     Size:2751
Attachment: kleenean.ecf     Size:1063
Attachment: kleenean.rc     Size:120
Attachment: kleenean_ancestor.e     Size:3598
Attachment: kleenean_ref.e     Size:2008
Attachment: test_kleenean.e     Size:3499