Recent backports of Nimbus fixes from JDK 7 into OpenJDK 6:

http://hg.openjdk.java.net/jdk6/jdk6/jdk/rev/c166019e1ee0
http://hg.openjdk.java.net/jdk6/jdk6/jdk/rev/464b2f754fc2
http://hg.openjdk.java.net/jdk6/jdk6/jdk/rev/89cabff3d834
http://hg.openjdk.java.net/jdk6/jdk6/jdk/rev/f4aead419975
http://hg.openjdk.java.net/jdk6/jdk6/jdk/rev/4edbcf36f4d4

have introduced a build failure:

../../../src/share/classes/com/sun/java/swing/plaf/nimbus/NimbusLookAndFeel.java:86: cannot find symbol
symbol : class NimbusDefaults
location: class com.sun.java.swing.plaf.nimbus.NimbusLookAndFeel
   private NimbusDefaults defaults;
           ^
../../../src/share/classes/com/sun/java/swing/plaf/nimbus/NimbusLookAndFeel.java:100: cannot find symbol
symbol : class NimbusDefaults
location: class com.sun.java.swing.plaf.nimbus.NimbusLookAndFeel
       defaults = new NimbusDefaults();
                      ^
../../../src/share/classes/com/sun/java/swing/plaf/nimbus/NimbusLookAndFeel.java:154: package NimbusDefaults does not exist
                   new NimbusDefaults.DerivedFont("defaultFont",
                                     ^
Note: Some input files use or override a deprecated API.
Note: Recompile with -Xlint:deprecation for details.
Note: Some input files use unchecked or unsafe operations.
Note: Recompile with -Xlint:unchecked for details.
3 errors
make[3]: *** [.compile.classlist] Error 1
make[3]: Leaving directory `/home/darcy/Sun/OpenJDK/6/hg/jdk6/jdk/make/javax/swing'
make[2]: *** [build] Error 1
make[2]: Leaving directory `/home/darcy/Sun/OpenJDK/6/hg/jdk6/jdk/make/javax'
make[1]: *** [all] Error 1
make[1]: Leaving directory `/home/darcy/Sun/OpenJDK/6/hg/jdk6/jdk/make'
make: *** [jdk-build] Error 2

This needs to be fixed.