As per the spec-
https://download.java.net/java/early_access/jdk22/docs/api/java.base/java/lang/foreign/SegmentAllocator.html#allocateFrom(java.lang.foreign.AddressLayout,java.lang.foreign.MemorySegment)

when the supplied MemorySegment is not 'native' then this method supposed to throw "UnsupportedOperationException" but actually it throws java.lang.IllegalArgumentException: Heap segment not allowed:

Sample code
====
 private void test01() {
        SegmentAllocator segmentAllocator = SegmentAllocator.prefixAllocator(Arena.ofAuto().allocate(1024));
        MemorySegment memorySegment = MemorySegment.ofArray(new int[10]);
        System.out.println("memorySegment is Native " + memorySegment.isNative());
        try {
            segmentAllocator.allocateFrom(ValueLayout.ADDRESS.withName("test"), memorySegment);
        } catch (Exception ex) {
            System.out.println("The ex is " + ex);
        }
    }
=====