VSS and ClearCase on same machine
Since I'm responsible for .NET and J2EE projects, I have two different IDE on my machine: VS.NET and WSAD (WebSphere Studio Application Developer). I use also two different source control tools: VSS for the .NET, Rational ClearCase for the J2EE.
After I've installed the ClearCase and worked some time on the WSAD, I wanted to switch to the VS.NET. So, naturally, I opened it up and tried to open our project. To my surprise, some strange error messages appeared. Those error messages, which were raised by VSS, stated that “The operation could not be completed.” After the messages - I couldn't open my project, and it was marked as “unavailable”.
I did some research on google, but couldn't find anything useful, that helped solve the problem. But - I did find some remarks stating that VSS and ClearCase on the same machine could be quite problematic.
Next station was the registry. After an extensive research, it turned out that there is a specific registry key that the IDE (both of them!) looks into to see whether a specific SourceControl is installed. For some unknown reason (to me), there is no value in there for source safe, only for ClearCase. This value should be removed prior using the VSS. If it is there - the VSS integration in VS.NET won't work.
So, here is a step by step instructions to re-enable VSS on a machine with ClearCase installed:
1. Open RegEdit
(Imagine that all the regular yada yada about the dangers in messing with the Registry is written right here.)
2. Navigate to: HKEY_LOCAL_MACHINE/SOFTWARE/SourceCodeControlProvider/InstalledSCCProviders
3. If ClearCase is installed, you should see one entry (besides the “(Default)”) named “ClearCase”, with the value “Software\Atria\ClearCase”. Remove the entry.
4. Now try to work with VSS under VS.NET. It should work.
If you would like to re-enable ClearCase later, simply add the entry mentioned above.
After a few rounds of adding / deleting from the registry, I became quite tired from this procedure, so I wrote a little tool which performs this exact task. If you're interested - email me and I'll send it back to you. Just remember that this tool requires the .NET runtime on your machine (quite obvious, but you can never know...)