Flakiness with test runner on win64-msvc2012_developer-build_qtnamespace_Windows_8

Hi
Maybe you're aware of this, but there seems to be some flakiness in the CI for win 8
I got this twice in a row, and it seems to sometimes fail while launching the testplanner script:

C:\strawberry\perl\bin\perl.exe C:\work\build_qtqa_latest\scripts\generic\testplanner.pl --input . --output testplan.txt --make nmake – -silent -o testresults.xml,xml -o -,txt
Can't spawn "cmd.exe": No such file or directory at C:/work/build/_qtqa_latest/scripts/qt/../lib/perl5/QtQA/TestScript.pm line 293.

First and second observed failures:
http://testresults.qt-project.org/ci/QtBase_stable_Integration/build_00465/win64-msvc2012_developer-build_qtnamespace_Windows_8/log.txt.gz

http://testresults.qt-project.org/ci/QtBase_stable_Integration/build_00468/win64-msvc2012_developer-build_qtnamespace_Windows_8/log.txt.gz

However, I can observe that it has succeeded after this:
http://testresults.qt-project.org/ci/QtBase_stable_Integration/build_00471/win64-msvc2012_developer-build_qtnamespace_Windows_8/log.txt.gz

This happened while trying to integrate https://codereview.qt-project.org/48319, (it shouldn't be related to this though)