Clang Code Model: Error: The clangbackend process has finished unexpectedly and was restarted.

Hi,

Since updating to QtCreator 4.11 (with Ubuntu 20.04), any time I try to open a C++ source file which is outside of my current project, the General Messages pane and the terminal where I launched QtCreator fill up with messages like this:

"ClangCodeModelConnectionClient" LocalSocket Error: "QLocalSocket: Remote closed"
2020-06-09T16:17:52 Clang Code Model: Error: The clangbackend process has finished unexpectedly and was restarted.
Error in ClangCodeModelServer::documentsClosed: Document '/.../path/to/toto.h' does not exists!

(where '/.../path/to/toto.h' is the exact path to the file outside my project which I opened), and syntax highlighting etc. does not work in the newly opened file (it continues to work in the files of the project).

This appears to be a regression.

Cheers

John