Now Creator has a problem similar to QTCREATORBUG-4307:

1. Open "Tools" -> "Options..." -> "Environment" -> "External Tools"
2. Select a tool.
3. Click into one of the edits for Executable, Arguments or Working directory.
4. Click on the appearing icon to open the Variables window.
5. Double-click one of the variables.
   The variable is being added to the edit.
6. Press ESC.
   The Options dialog is being closed.

Instead, ESC should close the Variables window only.

I guess the problem is, that the Options dialog gets focus after double-clicking the variable. When I click the variables windows before pressing ESC, only this is being closed.