Wrong make.exe called for manually added S60 SDKs

I usually duplicate S60 SDks manually on my harddisk, without using the S60 SDK installer. Then I 'subst' that duplicated SDK to be on a drive such as 't:\'. That's an old trick used by Symbian Pro's.

When I add that SDK manually to QtCreator, builds usually fail:

Running build steps for project QmlProject01...
Configuration unchanged, skipping qmake step.
Starting: C:/Program Files (x86)/Common Files/Symbian/Tools/make.exe debug-armv6 -w 
Can't open perl script "C:\Program": No such file or directory 
Exited with code 2.
Error while building project QmlProject01 (target: Symbian Device)
When executing build step 'Make'

I even add my device to 'c:\Program Files (x86)\Common Files\Symbian\devices.xml' just to make Creator a favor. I somehow assume that Creator needs the device to be in that list although I entered all relevant information manually. Nevertheless, the wrong make.exe is called. Instead of calling the one from the SDK (t:\Epoc32\tools\make.exe) it calls another one (C:/Program Files (x86)/Common Files/Symbian/Tools/make.exe).

See attached screenshot.

PS.: I remember having talked about that with either con or Tobias, but do not remember what the result was. So, this task here is at least a way to document that