Plugin is not compatible with JDKs (like temurin) which support changes of JEP 493 (do not include jmods folder)

[Bukama]

Affected version

3.0.0-SNAPSHOT (current master)

Bug description

Due the changes of JEP 493 (Java 24) some JDK, for example Temurin, do not ship a JMOD folder anymore. The plugin relies on this folder.

---

Old description

All IT are failing on master

(win 11, Java 25, with Admin rights)

D:\Github\Maven\maven-jmod-plugin>mvn -V
Apache Maven 4.0.0-rc-5 (fb3ecaef88106acb40467a450248dfdbd75f3b35)
Maven home: C:\apache-maven-4.0.0-rc-5
Java version: 25, vendor: Eclipse Adoptium, runtime: C:\JDK\Java25
Default locale: de_DE, platform encoding: UTF-8
OS name: "windows 11", version: "10.0", arch: "amd64", family: "winnt"

[ERROR] 
[INFO] -------------------------------------------------
[INFO] Build Summary:
[INFO]   Passed: 0, Failed: 18, Errors: 0, Skipped: 0
[INFO] -------------------------------------------------
[ERROR] The following builds failed:
[ERROR] *  base-config-cmds\pom.xml
[ERROR] *  base-config-headerfiles\pom.xml
[ERROR] *  base-config-legalnotices\pom.xml
[ERROR] *  base-config-libs\pom.xml
[ERROR] *  base-config\pom.xml
[ERROR] *  base-it\pom.xml
[ERROR] *  describe-base-config\pom.xml
[ERROR] *  describe-plain\pom.xml
[ERROR] *  list-base-config\pom.xml
[ERROR] *  list-plain\pom.xml
[ERROR] *  mjmod-20-set-main-class\pom.xml
[ERROR] *  mjmod-23-path-must-be-dir\pom.xml
[ERROR] *  mjmod-8-generate-jmod-in-other-project\pom.xml
[ERROR] *  non-default-config-cmds\pom.xml
[ERROR] *  non-default-config-headerfiles\pom.xml
[ERROR] *  non-default-config-legalnotices\pom.xml
[ERROR] *  non-default-config-libs\pom.xml
[ERROR] *  non-default-config\pom.xml

Most seen errors

assert artifact.isFile()
       |        |
       |        false

assert listLines == resourceNames
       |         |  |
       []        |  ['conf/config.test', 'classes/module-info.class', 'classes/myproject/HelloWorld.class']
                 false

assert expectedDescriptorLines == describeLines
       |                       |  |
       |                       |  []
       |                       false
       ['org.apache.maven.plugins.jmod.it.first@99.0', 'exports myproject', 'requires java.base']


[INFO]   java.lang.AssertionError: target file is missing or a directory.. Expression: (artifact.exists() && artifact.isFile())

[elharo]

works on my MacBook with Java 17. Is this still an issue for you @Bukama ?

[Bukama]

works on my MacBook with Java 17. Is this still an issue for you @Bukama ?

yes, it's one of many maven plugins where ITs are failing

[slachiewicz]

It's failing on Maven 4 - not maven 3

[Bukama]

It's failing on Maven 4 - not maven 3

That's not correct. They also fail with Maven 3.9.12

jmodpluginonmaven3912.log

[elharo]

If you look at a trivial PR like #89 we see that all ITs are passing, including on Windows including windows-latest jdk-25-zulu 3.9.12 (push). Is there a particular config we're missing where they are failing?

[Bukama]

If you look at a trivial PR like #89 we see that all ITs are passing, including on Windows including windows-latest jdk-25-zulu 3.9.12 (push). Is there a particular config we're missing where they are failing?

Didn't see any set in the maven-verify shared actions, so not sure.

When I look at the generated command that gets executed

Exit code: 2
Command line was: cmd.exe /X /C "C:\JDK\Java25\bin\jmod.exe create --module-version=99.0 --class-path=D:\Github\Maven\maven-jmod-plugin\target\it\base-config\target\classes --config=D:\Github\Maven\maven-jmod-plugin\target\it\base-config\src\main\configs --module-path=D:\Github\Maven\maven-jmod-plugin\target\it\base-config\target\classes;C:\JDK\Java25\jmods D:\Github\Maven\maven-jmod-plugin\target\it\base-config\target\jmods\maven-jmod-plugin-base-config.jmod"

and try to run it, it fails as there is a directory mentioned, which does not exists C:\\JDK\\Java25\\jmods

Fehler: Pfad nicht gefunden: C:\JDK\Java25\jmods

This directory does not exists in JDK 25 Temurin. Aside from the test test step failing is checking a .jmod file in the jmods folder of the ITs target folder.

def artifact = new File( target, 'jmods/maven-jmod-plugin-base-config.jmod' )

resulting in the absolute path of the tests: D:\Github\Maven\maven-jmod-plugin\target\it\base-config\target/jmods/maven-jmod-plugin-base-config.jmod. The "jmods" folder gets created, but no file in there (obvious - otherwise the test would succeeded).

In the create JmodMojo there is

            File jmodsFolderJDK = new File(javaHome, JMODS);
            getLog().debug("Parent: " + javaHome.getAbsolutePath());
            getLog().debug("jmodsFolder: " + jmodsFolderJDK.getAbsolutePath());

This path is not checked. If I add

            if(!jmodsFolderJDK.exists()) {
                throw new IOException("Jmods folder does not exists");
            }

it fails with exact that message

Caused by: java.io.IOException: Jmods folder does not exists

[Bukama]

And there will be no jmod with temurin actions/runner-images#13158

We provide software as it is distributed by official vendors, without modifications or additions whenever possible. If any components, such as jmods, have been removed from JDK 25, we cannot take responsibility for their absence or for the need to integrate them independently.

To summarize: The jmods plugin is not compatible with Temurin JDK 25

[Bukama]

I think it's related to JEP 493: Linking Run-Time Images without JMOD of Java 24

also see:

• https://unicorn-dev.medium.com/whats-new-in-java-24-2b1b9a702dc8
• [JDK 24] Enable JEP 493 in Temurin 24 builds adoptium/temurin-build#4035
• https://adoptium.net/news/2025/08/eclipse-temurin-jdk24-JEP493-enabled

[slachiewicz]

It's failing on Maven 4 - not maven 3

That's not correct. They also fail with Maven 3.9.12

jmodpluginonmaven3912.log

I'm looking into gha results (with Azul Java 25) and Your details about how to reproduce issue and You mentioned mvn4rc5.

So looks like we found root couse. With next release we may mention that it's not supported on Java 25 and maybe discontinue plugin.