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Did you solve the evil twin in ClearCase?

By Lettie Ar-Rahmaan posted Thu March 27, 2025 06:27 PM

  





If you’ve ever worked with IBM DevOps Code ClearCase (formerly IBM Rational ClearCase) in a multi-branch development environment, you might have encountered the dreaded evil twin. The "evil twin" occurs when two independent branches have the same file or directory name of a ClearCase VOB.  Therefore, when the files or directories are merged, it leads to merger conflicts. 

We know several admins have experienced this evil twin issue in ClearCase.  What did your team do to implement a trigger or policy to prevent them?

Share your experience — we’d love to hear how this classic ClearCase challenge has been tackled.


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Mon March 31, 2025 02:39 AM

This technote explains how to fix it:
https://www.ibm.com/support/pages/about-evil-twins

There's also documentation on how to prevent it:
https://www.ibm.com/docs/en/clearcase/11.0.0?topic=administration-managing-evil-twins