Clearcase equivalent to hg shelve - clearcase

Is there a ClearCase equivalent to hg shelve (or git stash for those of the other persuasion)? The closest I can think of is doing uncheckouts and saving keep files, but that means I'd have to hunt down the keep files afterwards, re-checkout the files and merge. I realize that ClearCase and Mercurial/Git have different philosophies behind them, but I'd be interested if there is any work in making ClearCase more "usable".

I listed a few for other version control tools, but none for ClearCase.
I explained, for ClearCase UCM, that a shelve command isn't easy to implement.
Instead of just saving the .keep files, you could save patches (unix diff between a .keep and its original version), since a patch can be re-applied later.
The other approach is to modify the config spec (easier when in a non-UCM view) in order to checking the currently modified versions in a new branch (see this config spec)
You can then decide to merge that branch later.

The philosophy is quite different.
In Clearcase, if you need to work on another branch/release, you usually have to use another Clearcase view. If you have Clearcase/UCM, it is even more true as you would use another view attached to another UCM stream. You would not be able to use the same view, whereas in Git, you would be able to stick to the same clone and perform a git stash, git checkout in order to start working on another release.
Now let's assume you need to work on another feature, for the same release. Under Clearcase/UCM, you would be able to create a new activity (cleartool mkact) and work on this new activity, using the same view. All the changes made will then be associated with this new activity. You will also be able to switch back to the previous activity using the command cleartool setact. The tricky part is if you need to deliver the activities separately. This will not necessarily possible as you might need to deliver both at the same time depending on the content of the changeset. This doc about determining dependent UCM activities is quite useful. If you need to move some changeset between activities, you can use the command cleartool chactivity with -fcset and -tcset options.
As a summary, with Clearcase UCM, if it is for different release, switch views and streams. If it is for the same release, play around with the UCM activities, knowing that it is less flexible than git stash.

Related

Clearcase equivalent of git no fast forward merge

What is the Clearcase equivalent of git's no fast forward (--no-ff) switch? Or how can I achieve the same functionality?
BACKGROUND
The situation is we are running multiple release branches and we need to be able to pull a feature or defect fix from the release branch if required. Currently (and I'm not the one managing Clearcase) all defect work is checked directly into the release branch, so backing out changes is time-consuming and potentially error-prone.
When using git with --no-ff, I can back out a feature or defect very quickly with minimal chance of causing an issue.
In ClearCase, you would instead cancel an activity (if you are using ClearCase UCM), or cancelling merges for a set of files with negative merges.
But there is no notion of "fast-forward": there is no HEAD to move, only versions (file by file) to merge. So if you know the merged versions, you can create new versions which cancel them (that is what the negative merge does).
There is no ff but there is also no HEAD in clearcase in the sense of git. The workflow is different. You always check in your code to a new checkin (or commit in git terminology). So it is like you are always doing a merge commit

How to capture all information from ClearCase?

I need some help on how to collect all information from ClearCase and tar or zip it, and store it in a provided space. we have migrated major baselines from ClearCase to different SCM tool .But we still have ClearCase. we want to capture all version, change, baseline, etc (basically capture everything but not the SCM tool itself) and zip it or put it in a flat file or so. this is just for historical purposes, so that tomorrow if someone wants to know what was in the ClearCase then they can see. so ,is there any idea?
The reason this doesn't exist (as far as I know) is in the nature of ClearCase (compared to a revision-based VCS tools).
It is a file-based VCS:
You create a new version for each file you change (instead of a unique repository-wide revision)
You create a label on each file you want to label (instead of a tag referring to a revision or a commit)
You create a branch for each file modified in that branch (instead of a single directory for SVN, or branch for other VCS)
...
That means you wouldn't simply export revisions/labels/branches with ClearCase. You would export them for each file: it doesn't scale well and would take too much time and space.
Migrating major baselines is sensible course of action that I have recommended before.
But for the rest, I always put a ClearCase instance as a way to explore the full history/events in case in is needed, while the recent history is managed in the new VCS tool.
Storing that as a flat file you could read without ClearCase isn't, again as far as I know, available.
Hence my previous "vobstore-reformatvob" proposition.

Reverting a users changes in ClearCase

We use ClearCase as control version system.
In our system sometimes we make releases without some developers commits because of time limit.
For example I made some changes in six classes but another user did changes in all or some of them also. And I have to commit code without his changes. So I scan my files with previous versions so that I can revert his changes. But it's a slow and boring process.
Is there another way to do that? Maybe an extension or a script?
The only way to automate that process is through:
subtractive merge or negative merge (as described in this IBM article):
cleartool merge -to filename -delete -ver \main\branch\version_number
cset.pl, which can take all the checkins of an UCM activity and cancel them.
See "Clearcase: how to rollback all changes on specific branch?".
But this is for UCM (which might not be your case)
In both cases, the idea is to create a new version which cancels the version of your other developer.

Is there RTC-equivalent "Suspend mode" in ClearCase?

I found "Suspend Change-set" in RTC to be very useful, and since we're working with ClearCase as well (dozens of users) I'm wondering if that feature is also available in ClearCase as well.
If not - could it be generated by script/trigger/hook ?
We use UCM, and I'd like to explain my question:
if I have to deliver and I want to skip delivering one activity, I can decide not to deliver it (if no dependencies...) , so my question is regarding working on my current stream: Is that possible to "suspend" an activity from my current stream ?
Thanks in advance
Simply put, not easily.
RTC is basically ClearCase rewritten from scratch, and the "suspend" mode (also called stashed or shelve) takes advantage of the notion of applying a changeset (to any state of a repository)
The UCM changeset are a list of versions of files. Each version is tied to its predecessor, and you cannot easily remove it (unless you do some negative or subtractive merges), and then re-apply them later.
That being said, Reuven just contacted me this morning, because he had files in checked out in a snapshot view on a Stream which he wants to rebase (similar issue to your deliver problem).
A possible way to do that is to create another view (dynamic one), which you can use for your rebase, and then go back to your snapshot view and update it: it will detect the updated config spec (following the rebase) and will not erase any of your currently checked out files.
On the checkin, those files will be merged with the updated version.

ClearCase : How Can I Revert to Earlier baseline?

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?
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.
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)
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 ;)
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)
The way I have solved this problem is by making another Stream, a child Stream of the Integration Stream. The easiest way to create this Stream is to open ClearCase Project Explorer (not Rational ClearCase Explorer) and navigate to the Project and then the Stream in question. Right click on the Integration Stream and select "Create Child Stream..."
Click "Advanced Options" and select a baseline for each component. Do this by selecting the component and then selecting "Change..." and selecting the specific baseline you want to see. You probably want to select "Prompt me to create a View for this Stream." Select "OK".
Any developer can do this. You don't need to be a VOB owner or Project or Stream owner.
Well, it depends. Actually, the answer lies in setting up your config spec to point to the proper files. Your config spec tells your view which versions of elements to look at. But how you do write it depends on your project's approach to baselines. Did you apply a label to mark that baseline? If so, and if you only want to read and not checkout anything new, your config spec can be as simple as
element * <LABELNAME>
If you didn't use labels, you can also set up your config spec to show you files based on dates. It gets more complicated the more rules you need to add to constrain your element choices. If you have more specifics, I can try to elaborate on what rules you might need. Otherwise, I would read the manuals that come with ClearCase. If you view the Extended Help from ClearCase Explorer, and then do "Viewing Rational ClearCase Manuals On-Line" it should give you some links to the Command References. This is where I go whenever I need to modify my config spec in some new way.
Also, note that we only use dynamic views, so I don't know if snapshot views work differently.

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