Hi, I'm getting unexpected end of stream / EOFException: \n not found: limit=0 from the consumer mock server. Java (Spring, not Spring Boot) app, pact-jvm consumer + consumer-junit5, client uses OkHttp 4.12.0. Reproduces on 4.7.3 and 4.6.15, with both KTorServer and JavaHttpServer. Not a DNS/localhost issue either — same result pointing the client at a literal 127.0.0.1:<port>. Fails every single run on both JDK 17 and JDK 25 (100% reproducible, even with -Djava.net.preferIPv4Stack=true). Minimal repro:

@ExtendWith(PactConsumerTestExt.class)
@PactTestFor(providerName = "example-provider", pactVersion = PactSpecVersion.V4)
class ExampleClientPactTest {

    private final OkHttpClient client = new OkHttpClient();

    @Pact(consumer = "example-consumer")
    public V4Pact createOrderPact(PactDslWithProvider builder) {
        return builder
            .given("provider accepts an order")
            .uponReceiving("a request to create an order")
            .path("/orders")
            .method("POST")
            .headers(Map.of("Content-Type", "application/json"))
            .body(new PactDslJsonBody()
                .stringType("customerId", "cust-123")
                .decimalType("amount", 100.00))
            .willRespondWith()
            .status(200)
            .headers(Map.of("Content-Type", "application/json"))
            .body(new PactDslJsonBody()
                .stringType("orderId", "order-456")
                .stringValue("status", "CREATED"))
            .toPact(V4Pact.class);
    }

    @Test
    @PactTestFor(pactMethod = "createOrderPact")
    void should_create_order(MockServer mockServer) throws IOException {
        Request request = new Request.Builder()
            .url(mockServer.getUrl() + "/orders")
            .post(RequestBody.create(
                "{\"customerId\":\"cust-123\",\"amount\":100.00}",
                MediaType.get("application/json")))
            .build();

        try (Response response = client.newCall(request).execute()) {
            assertThat(response.code()).isEqualTo(200);
        }
    }
}

Fails with:

java.io.IOException: unexpected end of stream on <http://localhost>:PORT/...

Caused by: java.io.EOFException: \n not found: limit=0 content=…

at okio.RealBufferedSource.readUtf8LineStrict

at okhttp3.internal.http1.HeadersReader.readLine

at okhttp3.internal.http1.Http1ExchangeCodec.readResponseHeaders

and Pact reports the interaction as not received (client never got a full response). Looks like a race where the client connects before the mock server is ready to respond. Anyone seen this / know a fix or workaround?

I ran your test in the Pact-JVM build, and it runs just fine. Tried both OkHttp 4.12.0 and 5.4.0.