After that, we can evaluate a fix in VS2022 if everything looks good in VS2026

I checked with the folk investigating, it did not repro in VS2026 and it did repro in VS2022 as they were trying different versions of VS and scenarios. When it did not repro, it did automatically rebuild.

Bruce, any chance you try VS2026 to confirm for your scenario in case any mismatch?

I believe it's the exact same repro steps as yours based on latest updates from DevCom.

Bruce, I assume you are using Dev17?

This is the feedback ticket: developercommunity.visualstudio.com/t/PCH-invali...

Hi Bruce, we were not able to reproduce, and we opened a feedback ticket for this issue on DevCom, could you add additional details there? How is the PCH produced? We tried to repro, and this seem to correctly invalidate the build and rebuild when the toolset is updated? Any repro much appreciated

yeah, was even better than Ex-Machina