The reproducer starts two threads, 1 for initialising Input/OutputStreams, the second which sets up a JavaShellToolBuilder which accepts these Streams as parameters.

The reason for "Pipe closed" is as follows:

This issue is seen when upgrading from jdk11.0.8 to jdk11.0.9. A major JLine upgrade went into this version (3.9.0) (https://bugs.openjdk.java.net/browse/JDK-8246176)

The bug seems to have been introduced in this upgraded source code, more specifically in the LineReaderImpl::readLine

Here is a snippet from lines 637-640:

Binding o = readBinding(getKeys(), local);
if (o == null) {
throw new EndOfFileException();
}

It appears when the program runs, this EndOfFileException is always thrown. When going deeper into the readBinding method, there is the BindingReader::readBinding method which makes a call to readCharacter(). This appears to always return a -1 (EOF) in the case of this reproducer and throws the Exception.

The reason this has not been caught earlier is because of https://bugs.openjdk.java.net/browse/JDK-8215438 “CTRL+D causes EOF”

 While this fix does indeed stop the CTRL+D error, by catching this error silently, it is allowing the JShell to exit quietly when an EOF is incorrectly caused by something else.