Vcpkg: How integration works

[alexkaratarakis]

The integration is done via a targets file. VS (MSBuild to be precise) has a couple of blessed folders; targets files within them are automatically loaded for every project.

For vcpkg, we have an immutable targets file that redirects to a per-user targets file (e.g. C:\Users\\AppData\Localvcpkgvcpkg.user.targets). This is done so each user can have separate settings and also so you can modify said settings without requiring admin privileges. vcpkg integrate install places the aforementioned vcpkg.user.targets files which enables VS integration.
(If you want to see the exact details, vcpkg\toolsrc\srccommands_integration.cpp is the source code for this functionality)

[JunielKatarn]

This is very confusing with multiple Visual Studio / VC installations.

Where exactly is the integration happening?
How exatly does MSBuild load vcpkg.user.targets?