If the root path to the top of the source tree on Windows exceeds 55 characters, the build on windows will fail. Some kind of path length limitation:

tail of failed build log on Windows X64/AMD64 (using MKS):
...
C:/mks/mksnt/cp ../../../../../src/share/classes/com/sun/inputmethods/internal/indicim/resources/DisplayNames.properties ../../../../../build/windows-amd64/tmp/sun/com.sun.inputmethods.internal.indicim/classes/com/sun/inputmethods/internal/indicim/resources/DisplayNames.properties
cp: Error copying file ../../../../../src/share/classes/com/sun/inputmethods/internal/indicim/resources/DisplayNames.properties to ../../../../../build/windows-amd64/tmp/sun/com.sun.inputmethods.internal.indicim/classes/com/sun/inputmethods/internal/indicim/resources/DisplayNames.properties: The system cannot find the path specified.
C:\jprt\slashjava\devtools\win32\bin\gnumake.exe[4]: *** [../../../../../build/windows-amd64/tmp/sun/com.sun.inputmethods.internal.indicim/classes/com/sun/inputmethods/internal/indicim/resources/DisplayNames.properties] Error 1
C:\jprt\slashjava\devtools\win32\bin\gnumake.exe[4]: Leaving directory `C:/jprt/temp/build/2006-06-15-203457.mchung.service_sdk_ws/source/make/com/sun/inputmethods/indicim'