windows failure in testsuite

Windows and testsuite folk: The testsuite framework is crashing on my 32-bit Windows machine, with the error below. Happens when the stderr output differs from expected. I know that there have been recent changes in the testsuite stuff. Could you fix please? Thanks Simon =====> T4254(normal) 1587 of 4522 [2, 15, 0] cd ./indexed-types/should_fail && "C:/code/HEAD/inplace/bin/ghc-stage2.exe" -c T4254.hs -fforce-recomp -dcore-lint -dcmm-lint -dno-debug-output -no-user-package-db -rtsopts -fno-warn-tabs -fno-ghci-history > T4254.comp.stderr 2>&1 Actual stderr output differs from expected: 'diff' is not recognized as an internal or external command, operable program or batch file.