Visual Studio IDE and MSBuild Incremental Build: Triggers for Full Rebuild

Goal: Determine which changes to a solution cause Visual Studio to bypass MSBuild's up‑to‑date checks and initiate a full rebuild instead of an incremental build.

Constraints: The behavior is not fully documented and varies between Visual Studio 2019 and 2022, between legacy .csproj and SDK‑style projects, and can be influenced by project file edits, imported .props/.targets files, or environment variable modifications.

Uncertainty: The exact set of triggers that cause Visual Studio to ignore MSBuild incremental logic remains unclear, leading to unpredictable build‑time overhead.

Specific questions:

• Which modifications to project files (e.g., .csproj, .props, .targets) reliably force a full rebuild?
• Does altering environment variables used in the build process always trigger Visual Studio to disregard MSBuild up‑to‑date checks?
• Are there differences in trigger behavior between Visual Studio 2019 and 2022 for the same change?