Git commands fail on windows when using the QProcess backend

For example when committing a change via the git commit editor just the Version Control output pane is shown with the following output:

07:02:28 Running in "C:\dev\src\qcr": "C:\Program Files\Git\cmd\git.exe" commit -F C:\Users\davschul\AppData\Local\Temp\QtCreator.menSeE --amend.
The command "C:\Program Files\Git\cmd\git.exe commit -F C:\Users\davschul\AppData\Local\Temp\QtCreator.menSeE --amend" could not be started.
Cannot commit 1 file(s).