This failed in the loom repo on Windows 10. I suspect this is nothing to do with loom, instead it's more likely due to the connection limit on Windows 10.

Echo server got HTTP_1_1 bytes: 38 4d617920746865206c75636b206f6620746865204972697368206265207769746820796f7521
May the luck of the Irish be with you!
test LineBodyHandlerTest.testAsStream("http://localhost:56645/http1/echo"): success
Echo server got HTTP_1_1 bytes: 38 4d617920746865206c75636b206f6620746865204972697368206265207769746820796f7521
May the luck of the Irish be with you!
test LineBodyHandlerTest.testAsStream("https://localhost:56646/https1/echo"): success
test LineBodyHandlerTest.testAsStream("http://localhost:56647/http2/echo"): failure
java.util.concurrent.CompletionException: java.net.ConnectException
at java.base/java.util.concurrent.CompletableFuture.encodeRelay(CompletableFuture.java:368)
at java.base/java.util.concurrent.CompletableFuture.completeRelay(CompletableFuture.java:377)
at java.base/java.util.concurrent.CompletableFuture$UniCompose.tryFire(CompletableFuture.java:1152)
at java.base/java.util.concurrent.CompletableFuture.postComplete(CompletableFuture.java:510)
at java.base/java.util.concurrent.CompletableFuture$AsyncSupply.run(CompletableFuture.java:1773)
at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1143)
at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:641)
at java.base/java.lang.Thread.run(Thread.java:1555)
Caused by: java.net.ConnectException
at java.net.http/jdk.internal.net.http.common.Utils.toConnectException(Utils.java:1045)
at java.net.http/jdk.internal.net.http.PlainHttpConnection.connectAsync(PlainHttpConnection.java:203)
at java.net.http/jdk.internal.net.http.PlainHttpConnection.checkRetryConnect(PlainHttpConnection.java:238)
at java.net.http/jdk.internal.net.http.PlainHttpConnection.lambda$connectAsync$1(PlainHttpConnection.java:214)
at java.base/java.util.concurrent.CompletableFuture.uniHandle(CompletableFuture.java:934)
at java.base/java.util.concurrent.CompletableFuture$UniHandle.tryFire(CompletableFuture.java:911)
... 5 more
Caused by: java.nio.channels.ClosedChannelException
at java.base/sun.nio.ch.SocketChannelImpl.ensureOpen(SocketChannelImpl.java:202)
at java.base/sun.nio.ch.SocketChannelImpl.beginConnect(SocketChannelImpl.java:786)
at java.base/sun.nio.ch.SocketChannelImpl.connect(SocketChannelImpl.java:874)
at java.net.http/jdk.internal.net.http.PlainHttpConnection.lambda$connectAsync$0(PlainHttpConnection.java:187)
at java.base/java.security.AccessController.doPrivileged(AccessController.java:569)
at java.net.http/jdk.internal.net.http.PlainHttpConnection.connectAsync(PlainHttpConnection.java:189)
... 9 more