Steps to reproduce:

• Create a general empty project in DS
• Enable automatic cmake generation (File -> Export project -> Enable automatic cmake generation)
• Open and configure project in QtCreator (latest released version 13.0.0):
  • Creator suggest by default a build path that's inside the DS project: shorten it a bit but leave inside the project, e.g. <projectpath>\build\release
• Build project
• -> build succeeds as expected
• In DS side, add e.g. Rectangle component to the project and save all changes
• In Creator, build the project again
• -> Build fails with cmake errors. see attached output.

Additional information:

• I tested this with same steps (expect for cmake generation, those I created manually after changes from File -> Export project -> Generate cmake build files) using QDS4.4 and did not encounter this issue. 
• If I use a build folder that's not inside the DS project directory, issue does not reproduce