And I also found that switching to a different workspace may re-write correct .depend files with empty ones.
More details:
- Loaded a smaller workspace. Edited at least one .cpp file in each project. Built each project after the edit. .depend files are correct
- Loaded a larger workspace that included all the projects from the smaller one plus some more. Edited a .cpp file in a new project. Built the project. .depend file for that project became correct, but all other .depend files became empty.
From my experiments it looks that .depend generation algorithm contains a bug (at least on Linux x86_64) which may be triggered when a new "superset" workspace is loaded and built.
Perhaps it would be helpful to have a "manual overdrive" to re-generate .depend files, probably somewhere in advanced options.