Jikes requires a reference to the boot class path to work properly in the JDK 1.2 or later environment.  The patch below allows the bootclasspath attribute to be coded on the Javac action (it is currently ignored if build.compiler == jikes)
 
Why bother?  So that Javac actions can be coded with extdir and bootclasspath and work equally well either with classic or Jikes.  The only change required is the build.compiler property itself.
 
Here is the patch:
 
--- Javac.java Wed May 10 16:20:34 2000
+++ Javac.java.new Sat May 13 15:45:17 2000
@@ -456,6 +456,13 @@
         StringBuffer classpath = new StringBuffer();
         classpath.append(getCompileClasspath());
 
+        // Jikes doesn't support bootclasspath dir (-bootclasspath)
+        // so we'll emulate it for compatibility and convenience.
+        if (bootclasspath != null) {
+            classpath.append(File.pathSeparator);
+            classpath.append(project.translatePath(bootclasspath));
+        }
+
         // Jikes doesn't support an extension dir (-extdir)
         // so we'll emulate it for compatibility and convenience.
         addExtdirsToClasspath(classpath);