Test_org_eclipse_swt_dnd_Clipboard failing on I-build tests on some platforms

[jonahgraham]

My new test for the clipboard PR #2541 (part of #2126) doesn't work on all platforms.

I-build I20250926-0030/
Test_org_eclipse_swt_dnd_Clipboard pass/fail:

Linux x64, Java 21: Pass
Linux x64 Java 25: Pass
mac x64: Fail
mac arm: Still waiting
Windows: Still waiting

This test passes on all the GitHub action runners

---

The test fails on macOS in the RMI code with a couple of different, but similar, exceptions

Error unmarshaling return header; nested exception is: java.net.SocketException: Connection reset

java.rmi.UnmarshalException: Error unmarshaling return header; nested exception is:
java.net.SocketException: Connection reset
at java.rmi/sun.rmi.transport.StreamRemoteCall.executeCall(StreamRemoteCall.java:255)
at java.rmi/sun.rmi.server.UnicastRef.invoke(UnicastRef.java:382)
at java.rmi/sun.rmi.registry.RegistryImpl_Stub.lookup(RegistryImpl_Stub.java:123)
at org.eclipse.swt.tests.junit.Test_org_eclipse_swt_dnd_Clipboard.startRemoteClipboardCommands(Test_org_eclipse_swt_dnd_Clipboard.java:175)
at org.eclipse.swt.tests.junit.Test_org_eclipse_swt_dnd_Clipboard.openAndFocusRemote(Test_org_eclipse_swt_dnd_Clipboard.java:107)
at org.eclipse.swt.tests.junit.Test_org_eclipse_swt_dnd_Clipboard.test_getContents(Test_org_eclipse_swt_dnd_Clipboard.java:296)
at java.base/java.lang.reflect.Method.invoke(Method.java:580)
at java.base/java.util.ArrayList.forEach(ArrayList.java:1596)
at java.base/java.util.ArrayList.forEach(ArrayList.java:1596)
Caused by: java.net.SocketException: Connection reset
at java.base/sun.nio.ch.NioSocketImpl.implRead(NioSocketImpl.java:318)
at java.base/sun.nio.ch.NioSocketImpl.read(NioSocketImpl.java:346)
at java.base/sun.nio.ch.NioSocketImpl$1.read(NioSocketImpl.java:796)
at java.base/java.net.Socket$SocketInputStream.read(Socket.java:1099)
at java.base/java.io.BufferedInputStream.fill(BufferedInputStream.java:291)
at java.base/java.io.BufferedInputStream.implRead(BufferedInputStream.java:325)
at java.base/java.io.BufferedInputStream.read(BufferedInputStream.java:312)
at java.base/java.io.DataInputStream.readUnsignedByte(DataInputStream.java:295)
at java.base/java.io.DataInputStream.readByte(DataInputStream.java:275)
at java.rmi/sun.rmi.transport.StreamRemoteCall.executeCall(StreamRemoteCall.java:241)
... 8 more

and

Error unmarshaling return header; nested exception is: java.io.EOFException

java.rmi.UnmarshalException: Error unmarshaling return header; nested exception is:
java.io.EOFException
at java.rmi/sun.rmi.transport.StreamRemoteCall.executeCall(StreamRemoteCall.java:255)
at java.rmi/sun.rmi.server.UnicastRef.invoke(UnicastRef.java:382)
at java.rmi/sun.rmi.registry.RegistryImpl_Stub.lookup(RegistryImpl_Stub.java:123)
at org.eclipse.swt.tests.junit.Test_org_eclipse_swt_dnd_Clipboard.startRemoteClipboardCommands(Test_org_eclipse_swt_dnd_Clipboard.java:175)
at org.eclipse.swt.tests.junit.Test_org_eclipse_swt_dnd_Clipboard.openAndFocusRemote(Test_org_eclipse_swt_dnd_Clipboard.java:107)
at org.eclipse.swt.tests.junit.Test_org_eclipse_swt_dnd_Clipboard.test_Remote(Test_org_eclipse_swt_dnd_Clipboard.java:220)
at java.base/java.lang.reflect.Method.invoke(Method.java:580)
at java.base/java.util.ArrayList.forEach(ArrayList.java:1596)
at java.base/java.util.ArrayList.forEach(ArrayList.java:1596)
Caused by: java.io.EOFException
at java.base/java.io.DataInputStream.readUnsignedByte(DataInputStream.java:297)
at java.base/java.io.DataInputStream.readByte(DataInputStream.java:275)
at java.rmi/sun.rmi.transport.StreamRemoteCall.executeCall(StreamRemoteCall.java:241)
... 8 more

[jonahgraham]

In these cases the application is starting successfully, at least until

eclipse.platform.swt/tests/org.eclipse.swt.tests/data/clipboard/ClipboardTest.java

Lines 118 to 119 in 34becc0

	rmiRegistry = LocateRegistry.createRegistry(chosenPort);
	System.out.println(ClipboardCommands.PORT_MESSAGE + chosenPort);

I know this because the ClipboardTest is providing the port that it is listening to as the exception is happening when trying to get remote service.

My first guess is one of:

• the macOS machines used for tests have some security policies preventing connection
• the macOS machines have a problem with Swing and the remote app is failing when trying to create the Swing UI, causing app to quit and connections to fail

[jonahgraham]

While testResults are still blank, I can see that macOS aarch suffers the same problem on Jenkins

The Windows tests have not run, I don't understand why yet, but it looks like ant didn't exist on the machine? Previous builds look the same so not sure what changed.

From the WIndows console output:

04:09:07  C:\Users\genie.releng\workspace\AutomatedTests\ep438I-unit-win32-x86_64-java21>ant -f getEBuilder.xml -DbuildId=I20250926-0030             -Dosgi.os=win32 -Dosgi.ws=win32 -Dosgi.arch=x86_64             -DtestSuite=all 
04:09:07  'ant' is not recognized as an internal or external command,
04:09:07  operable program or batch file.