Uninstalling an in-use shared assembly leaving WinSxs in a bad state.

Question

I am having troubles uninstalling a shared win32 SxS assembly using Wix3 on WinXP. My wix file looks pretty much like the one described in http://n2.nabble.com/Tutorial-How-to-install-files-into-WinSxS-td841475.html.

The problem is, if a module from the assembly is in use, the uninstaller completes with a success errorcode but leaves the assembly in a broken state: the manifest and security catalogue have been deleted, but the assembly directory still exists with my dlls in it. The DLLs survive reboots, so are not marked for deletion in any way. There are no obvious errors in the MSI log file.

If I try re-installing the package, it skips installation of the assembly. The components are no longer registered, so I can't get Installer to try uninstalling again. The following is shown in the msi log on subsequent installs:

MSI (c) (98:44) [11:46:56:263]: skipping installation of assembly component: {26A273E7-7F9A-4F77-9FA8-5E413A155BEC} since the assembly already exists

I can't find a way of bringing the SxS back into a good state short of manually deleting my assembly's directory, which at this point is no longer being protected by XP System Restore.

While my actual installer is much more complicated, I have been able to reproduce this with a very basic installer that has a single feature containing a single component. That component contains a dll, a manifest and a security catalogue. The dlls <File> element has KeyPath, Assembly and AssemblyManifest attributes set. Once installed, I can simulate a process loading the assembly by opening the DLL in MSVS.

Is there an extra action I should be invoking on uninstall to detect and prevent this situation? Alternatively, is there a way of forcing the install operation to be performed even though the DLLs already exist in WinSXS?

Somewhat related, I also have a problem if I try to upgrade the package that installed the assembly if the assembly is not changing. The installer decides that it does not need to reinstall the assembly (since it has not changed), but then when the SxsUninstallCA runs, it goes and removes the assembly. From Installer's point of view, the component is still installed, but the files are gone.

Answer 1

I'm working on something which I believe I'll run into this same problem.

My assumption at this point is that I’d have to solve this with a little mojo from the HKLM\SYSTEM\CurrentControlSet\Control\Session Manager\PendingFileRenameOperations regkey, and a possibly bit of file permission smacking (if the files were still locked).

Which of course, requires a reboot.

Of course, in your installer, you could check for the presence of the keys and block on install until they're gone. (ie "you need to reboot").