I use windows, it has the same error.
Reason:
- The problem QTCreator runs hg.exe from the folder where you launch QTCreator and of course there is no .hg folder in QTCreator program folder.
Solution:
- Launch QTCreator from folder where you store the repository (folder which continas .hg folder)
- For windows, create a shortcut for QTCreator and in property of that shortcut, choose startIn the folder which contain .hg folder