Cpptools configuration issue after building

I'm not sure if I should open a new issue, but I also have this issue. It happens randomly and there's nothing special in the C++ extension logs. IntelliSense works perfectly, but then after triggering a build by pressing `F7`, it sometimes starts to fail and I get the "#include errors detected" error. Resetting the IntelliSense database works sometimes, and restarting extension host seems to fix it 100% of the time.

_Originally posted by @grigorig in https://github.com/microsoft/vscode-cmake-tools/issues/1563#issuecomment-762669090_

Start by reproducing the failure after pressing F7, then compare IntelliSense behavior before and after the build. The issue mentions the C++ extension logs, resetting the IntelliSense database, and restarting the extension host; use those observations to narrow the interaction. Done means a build no longer leaves IntelliSense reporting “#include errors detected”.

Written by the indexing model from the issue text.