Maven 4.0.0-rc-6 hangs on startup with JDK 25 in a Linux container environment

[kressi]

Summary

mvn --version hangs indefinitely with Maven 4.0.0-rc-6 under JDK 25 in a Linux container environment.

The same command works with Maven 4.0.0-rc-5under the same conditions.

This appears to be a regression in rc-6.

Environment

• OS: Linux (container)
• Container image: openjdk:25-ea-jdk-bullseye
• Java: OpenJDK 25
• Maven versions compared:
  • 4.0.0-rc-5 (works)
  • 4.0.0-rc-6 (hangs)

Regression statement

Under the sam eruntime and command line:

• apache-maven-4.0.0-rc-5/bin/mvn --batch-mode --errors --show-warnings --version exits successfully
• apache-maven-4.0.0-rc-6/bin/mvn --batch-mode --errors --show-warnings --version hangs and must be killed

Reproduction (self-contained, JDK-only)

This script below avoids external package installs and uses only JDK tools available in the image.

docker run --rm -it openjdk:25-ea-jdk-bullseye bash -ilc '
mkdir -p /tmp/mvncmp
cd /tmp/mvncmp

cat <<"EOF" > Downloader.java
import java.io.InputStream;
import java.net.URI;
import java.nio.file.*;

public class Downloader {
  public static void main(String[] args) throws Exception {
    try (InputStream in = URI.create(args[0]).toURL().openStream()) {
      Files.copy(in, Paths.get(args[1]), StandardCopyOption.REPLACE_EXISTING);
    }
  }
}
EOF

for v in 4.0.0-rc-5 4.0.0-rc-6; do
  url="https://archive.apache.org/dist/maven/maven-4/${v}/binaries/apache-maven-${v}-bin.zip"
  zip="apache-maven-${v}-bin.zip"
  dir="apache-maven-${v}"

  echo "Downloading ${url}"
  /usr/local/openjdk-25/bin/java Downloader.java "${url}" "${zip}"

  mkdir -p "${dir}"
  (cd "${dir}" && /usr/local/openjdk-25/bin/jar xf "../${zip}")
  mv "${dir}/apache-maven-${v}"/* "${dir}"
  rmdir "${dir}/apache-maven-${v}"
  chmod +x "${dir}/bin/mvn"

  echo "== ${v} =="
  timeout -k 5s 40s "${dir}/bin/mvn" --batch-mode --errors --show-version --version
  echo "rc=$?"
done
'

Expected result

Both versions print Maven version and exit with code 0.

Actual result

• rc-5: exits with 0
• rc-6: hangs; timeout kills process (rc=124 from timeout wrapper, process termination observed)

Thread dump evidence from rc-6

While hung, jcmd <pid> Thread.print -l shows:

• main thread waiting in CompleteableFuture.get() from org.apache.maven.jline.FastTerminal.getTerminal
• a separate fast-terminal-thread also waiting in the same path
• stack includes Jline FFM terminal provider intitialization (org.jline.terminal.impl.ffm.CLibrary)

Relevant frames:

"main" ... WAITING (parking)
at java.util.concurrent.CompletableFuture.get
at org.apache.jline.FastTerminal.getTerminal(FastTerminall.java:68)
at org.apache.jline.FastTerminal.getType(FastTerminal.java:201)
at org.apache.slf4j.MavenSimpleLogger.configure(...)
at org.apache.cling.invoker.LookupInvoker.activeLogging(...)

"fast-terminal-thread"  ... WAITING (parking)
at java.util.concurrent.CompletableFuture.get
at org.apache.maven.jline.FastTerminal.getTerminal(FastTerminal.java:68)
...
at org.jline.terminal.impl.ffm.CLibrary.<clinit>(CLibrary.java:369)

Also seen during startup:

WARNING: Unable to find openpty native method in static libraries and unable to load the util library.
- java.long.UnsatisfiedLinkError: no util in java.library.path: ...

Suspected cause

A startup hang/regression in Maven 4.0.0-rc-6 involving JLine terminal initialization (FFM path) and logging initialization.

The issue does not reproduce in 4.0.0-rc-5 with the same JDK and container.

Workarounds

Any of the following avoids the hang for rc-6 in this environment:

• MAVEN_OPTS="-Dorg.jline.terminal.ffm=false"
• MAVEN_OPTS="-Dorg.jline.terminal.ffm=false -Dorg.jline.terminal.jni=true"
• MAVEN_OPTS="-Dorg.jline.terminal.providers=jni,exec -Dorg.jline.terminal.ffm=false"

Notes

• This is reproducible with mvn --version only (no project build required).
• Network/download issues were ruled out.
• Wrapper script is not required to reproduce; direct Maven binary invocation shows the same behavior for rc-6.

[Adarsh-Me]

Hi, I'd like to investigate this and work on a fix. Could you please assign it to me?