ClearCase : How Can I Revert to Earlier baseline?

Question

How Can I Revert to Earlier baseline? We have a UCM parallel development(multi-stream) project. Each developer have a snapshot view on Project's Integration stream. Developers want to see earlier version of the application in their snapshot views so They can debug early version of application to find bugs.

When I want to change an existing snapshot views's foundition baselines, clearcase does not allow me. So How Can I do this?

Answer 1

Since you employ the term Baseline, I will assume you are using UCM.

On a stream, you can not revert backward a baseline.

One possibility is to make a parallel stream, with the desired baseline as foundation: this is the quickest way.

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After changes on this new stream, you can make a new rebase to change the foundation baseline, but only if that new rebase is using a more recent baseline from the parent stream (not an older baseline)

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For your specific need, I would recommand a non-UCM snapshot view with a simple rule

element * thePreviousBaseline

In order for the developer to have:

• his/her current UCM view for development (always set on the LATEST of a branch associated to a stream)
• a second snasphot view set to whatever baseline he/she needs.

That second snapshot view is completely not-related to the UCM project and takes advantage of the "full" nature of the baseline (do check that your baseline has been put as "full", not "incremental". If it is "incremental", simply change its type and upgrade it to full)

So, beside your current snapshot UCM view, you can create anywhere you want a non-snasphot view:

cleartool mkview -snap -tag mylogin_myComponentname_csl_snap -vws myPathToViewStorage myPathToRootView
cd myPathToRootView
cleartool edcs
[add the selection rule: element * myOlderBaseline]
[add the load rule at the end: 'load /myVob_Including_MyComponent]
[save, type 'yes']

That is fine for consultation/execution, but if you need to patch (that i is to write, check out and in some files), then I would recommend one UCM stream per baseline to be patched.
That way, the stream clearly represents the patch effort for a given baseline. There should not be too many of them, unless you put into production a new version of your application every five minutes... which is not advisable ;)

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So to summarize:

• the non-UCM snapshot view is unique and serve for a quick consultation/debug of one older baseline at a time.
• for patches (source modification), you create a parallel stream properly named, with the correct foundation baseline, and then a UCM view on it. You can not only debug but also fix some bugs in an activity, the deliver that activity to the main Int stream if that bug need to be retro-fitted on an higher stream.
  (note: all bugs do not always need to be delivered: they can be obsolete when compared with the current state of the development)