swt-gtk fails to build on arm, sparc, m68k

[Shaun Jackman <sjackman@gmail.com>]

swt-gtk 3.0+3.1M4-3 builds successfully on ia64, hppa, alpha, s390 and
powerpc, but it failed to build on arm, sparc, and m68k. The package
is being built using gcj-3.3. The error message is...

org/eclipse/swt/internal/Platform.java:0: error: Can't find default
package `java.lang'. Check the CLASSPATH environment variable and the
access to the archives

http://buildd.debian.org/build.php?pkg=swt-gtk

Could someone give me a hint on what's gone wrong here?

Please cc me in your reply. Thanks,
Shaun