If you installed the initial release of Sun Studio 12 update 1 (around June of 2009) you might have some problems running the uninstall script that came with it.  Our installer guru came up with a “workaround” script which is now available for download on the Sun Download Center.  You can find a description of the problems and a link to the script on the Sun Studio web site’s Troubleshooting Page.  You may also find it useful to check the Sun Studio 12 update 1 installation guide.  Some of the failure modes may show you errors like this:

The local registry (/root/.nbi/registry.xml) could not be loaded, or was loaded partially.
The installer can continue to work normally, but doing so may result in a corrupted global registry.

As Sun moves towards using the IPS packaging system, we’ll be able to rely more on the packaging tools built in to Solaris, and we won’t have as many issues like these.  I’m looking forward to it.