A DESCRIPTION OF THE PROBLEM :
Can't get annotations that are present on packages in -Xbootclasspath/a.

Perhaps the cause of this problem is that the class loader for -Xbootclasspath/a
(jdk.internal.loader.ClassLoaders.BOOT_LOADER) can't reference the class java.lang.Object
loaded by the bootstrap class loader.

Because the class package-info extends the class java.lang.Object,
the class java.lang.Object is loaded or referenced in defining the class package-info.

If the class package-info is in -Xbootclasspath/a,
the class loader for -Xbootclasspath/a tries to load the class java.lang.Object.

But the class loader for -Xbootclasspath/a can't reference the class java.lang.Object
loaded by the bootstrap class loader.

So, the class loader for -Xbootclasspath/a tries to find and define the class java.lang.Object.

Then an exception occurrs because ClassLoader.preDefineClass prohibits class loaders
other than the platform class loader from loading classes in packages "java.*".

Perhaps this problem occurrs Package.getPackageInfo only.
Loading the class package-info in -Xbootclasspath/a by Class.forName
or ClassLoader.loadClass is successful.

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
1. compile a bootclasspath library
cd boot-lib
javac sample/MyAnnotation.java sample/Foo.java sample/package-info.java
jar cf ../boot-lib.jar sample/MyAnnotation.class sample/Foo.class sample/package-info.class
cd ..

2. compile a sample application
javac -cp boot-lib.jar Sample.java

3. run the sample with boot-lib.jar on bootclasspath
java -Xbootclasspath/a:boot-lib.jar -cp . Sample

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
Print "Success"
ACTUAL -
Exception occurred.

Exception in thread "main" java.lang.SecurityException: Prohibited package name: java.lang
        at java.base/java.lang.ClassLoader.preDefineClass(ClassLoader.java:898)
        at java.base/java.lang.ClassLoader.defineClass(ClassLoader.java:1106)
        at java.base/java.security.SecureClassLoader.defineClass(SecureClassLoader.java:206)
        at java.base/jdk.internal.loader.BuiltinClassLoader.defineClass(BuiltinClassLoader.java:761)
        at java.base/jdk.internal.loader.BuiltinClassLoader.findClassInModuleOrNull(BuiltinClassLoader.java:682)
        at java.base/jdk.internal.loader.BuiltinClassLoader.loadClassOrNull(BuiltinClassLoader.java:607)
        at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:581)
        at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:521)
        at java.base/java.lang.ClassLoader.defineClass1(Native Method)
        at java.base/java.lang.ClassLoader.defineClass(ClassLoader.java:1016)
        at java.base/java.security.SecureClassLoader.defineClass(SecureClassLoader.java:174)
        at java.base/jdk.internal.loader.BuiltinClassLoader.defineClass(BuiltinClassLoader.java:802)
        at java.base/jdk.internal.loader.BuiltinClassLoader.findClassOnClassPathOrNull(BuiltinClassLoader.java:700)
        at java.base/jdk.internal.loader.BuiltinClassLoader.findClass(BuiltinClassLoader.java:568)
        at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:633)
        at java.base/java.lang.Package.getPackageInfo(Package.java:420)
        at java.base/java.lang.Package.getAnnotations(Package.java:467)
        at Sample.main(Sample.java:5)

---------- BEGIN SOURCE ----------
- boot-lib/sample/MyAnnotation.java
package sample;

import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

@Target(ElementType.PACKAGE)
@Retention(RetentionPolicy.RUNTIME)
public @interface MyAnnotation {
}

- boot-lib/sample/Foo.java
package sample;

public class Foo {
}

- boot-lib/sample/package-info.java
@MyAnnotation
package sample;

- Sample.java
public class Sample {
    public static void main(String[] args) {
        Class<?> c = sample.Foo.class;
        Package p = c.getPackage();
        p.getAnnotations();
        System.out.println("Success");
    }
}

---------- END SOURCE ----------

FREQUENCY : always