Clang Tools: can't analyze a header file

Clang Tools analysis of a C(++) header is impossible with Qt Creator - the error is shown in Issues pane:

:-1: error: Cannot analyze current file: "/home/bam/kde/src/kwin/src/main.h" is not a known source file.

The same file can be analyzed with CLI Clang-Tidy just fine.

Tried on CMake-based KWin project:
https://invent.kde.org/plasma/kwin

To reproduce:
right-click on the header source, from the context menu choose Analyze Current File item 

An upstream issue at CMake was opened up, not mush progress so far:
file-api: add ability to query for header files (#24359) · Issues · CMake / CMake · GitLab (kitware.com)