Registering an unpacked VSIX extension via MSI without using devenv /setup

Question

We have a Visual Studio extension, currently installed with MSI, since we need to perform certain tasks after the installation (ngen, registering certain COM servers, etc). In t

Answer 1

As Jason (and everyone else) suggests - yes, the "correct" (supported) way of registering a Visual Studio package externally is by running devenv.exe /setup, and for the most part - it works without problems (albeit slow, due to entire Visual Studio configuration being rebuilt).

This is a commercial product, and every once in a while we get a support case, complaining that after installing our extension, something bad happened in Visual Studio - other extensions failed to load, problem with Solution explorer, etc. Those cases are rare, but they do happen.

In an attempt to minimize the impact installing our extension does to the user's machine, I was trying to find a suitable way to use the VSIX installation mechanism that does not use devenv.exe /setup, but unfortunately, there isn't a supported scenario that handles all the issues I've raised in the question above.

After extensive research into the problem, I found an undocumented, unsupported solution that solves the problem completely! An empty file, called extensions.configurationchanged, located under %VSInstallDir%\Common7\IDE\Extensions gets touched every time a VSIX package is installed or uninstalled, causing Visual Studio to refresh it's package cache (only!) on next restart! With modifying this file's "last modified date", it will essentially cause Visual Studio to act as if a VSIX package was just installed or uninstalled.

A few quick experiments of copying the extension files to an empty hive, and then touching the extensions.configurationchanged will cause Visual Studio to load the extension (and process all its .pkgdef files) on next restart - no devenv /setup necessary!

Several commercial products offer this solution in the Troubleshooting section of their online help, dealing with loading failure of their extension, so this solution might be the "lesser evil" I was looking for.

Use at your own risk.