Windows build fails with the following error:
=============================================
rm -f c:/java/mustang-build/tmp/sun/sun.tools.javazic/.classes.list

if [ -s c:/java/mustang-build/tmp/sun/sun.tools.javazic/.classes.list ] ; \

then /cygdrive/c/java/1.6.0b31/bin/javac -J-client -J-XX:ThreadStackSize=768 -J-Xms64m -J-Xmx256m -classpath c:/java/mustang-build/classes -bootclasspath "c:/java/mustang-build/lib/jce.jar;c:/java/mustang-build/lib/jsse.jar" -sourcepath "c:/java/mustang-build/gensrc;../../../src/windows/classes;../../../src/share/classes" -d c:/java/mustang-build/classes -encoding ascii -source 1.5 -d c:/java/mustang-build/tmp/sun/sun.tools.javazic \

     ; \

fi

rm -f -r c:/java/mustang-build/tmp/sun/sun.tools.javazic/zi

/cygdrive/c/java/1.6.0b31/bin/java -classpath c:/java/mustang-build/tmp/sun/sun.tools.javazic sun.tools.javazic.Main -V "`cat ./tzdata/VERSION`" -d c:/java/mustang-build/tmp/sun/sun.tools.javazic/zi ./tzdata/africa ./tzdata/antarctica ./tzdata/asia ./tzdata/australasia ./tzdata/europe ./tzdata/northamerica ./tzdata/pacificnew ./tzdata/southamerica ./tzdata/systemv ./tzdata/backward ./tzdata/etcetera ./tzdata/solar87 ./tzdata/solar88 ./tzdata/solar89 ./tzdata/systemv ./tzdata_jdk/gmt ./tzdata_jdk/jdk11_backward

Exception in thread "main" java.lang.NoSuchMethodError: sun.util.calendar.Gregorian.newCalendarDate(Ljava/util/TimeZone;-)Lsun/util/calendar/Gregorian$Date;

at sun.tools.javazic.Time.getLocalTime(Time.java:190)

at sun.tools.javazic.Time.getLocalTime(Time.java:176)

at sun.tools.javazic.ZoneRec.getLocalUntilTime(ZoneRec.java:113)

at sun.tools.javazic.ZoneRec.parse(ZoneRec.java:222)

at sun.tools.javazic.Zoneinfo.parse(Zoneinfo.java:247)

at sun.tools.javazic.Main.compile(Main.java:100)

at sun.tools.javazic.Main.main(Main.java:137)

make: *** [c:/java/mustang-build/tmp/sun/sun.tools.javazic/zi/ZoneInfoMappings] Error 1
=============================================

This happens because newCalendarDate method is declared in the base class with the different return type. The return type in sun.util.calendar.Gregorian class is a sub-class of the type used in the base class, so "covariant return types" feature should work. But due to some reason it doesn't. The following changes fix the problem:
*** /tmp/geta12576.B12579 2005-05-12 16:44:57.045129352 +0400
--- Gregorian.java 2005-05-12 16:44:54.957446728 +0400
***************
*** 59,69 ****
   return getCalendarDate(millis, newCalendarDate(zone));
      }
  
! public Date newCalendarDate() {
   return new Date();
      }
  
! public Date newCalendarDate(TimeZone zone) {
   return new Date(zone);
      }
  }
--- 59,69 ----
   return getCalendarDate(millis, newCalendarDate(zone));
      }
  
! public CalendarDate newCalendarDate() {
   return new Date();
      }
  
! public CalendarDate newCalendarDate(TimeZone zone) {
   return new Date(zone);
      }
  }

###@###.### 2005-05-12 12:48:12 GMT