Can't specify Java 25 as compiler

[thomasa299792]

Tycho fails if I specify Java 25 as a compiler release. Works with Java 21.

Tycho error message says "release version 25 is not supported."

My JAVA_HOME environment variable is pointing to a Java 25 SDK.

Eclipse 5.0.0 was released Aug. 29. Afterwards, Java 25 was released Sept. 16.

Configuration in a pom.xml:

<project ...> 
 <properties>
  	<tycho.version>5.0.0</tycho.version>
        <maven.compiler.release>25</maven.compiler.release>
        ...

Error message:

[exec] [ERROR] Failed to execute goal org.eclipse.tycho:tycho-compiler-plugin:5.0.0:compile (default-compile) on project com.dnastar.common: Fatal error compiling: release version 25 is not supported -> [Help 1]

Is there a workaround for this?

Is there an upcoming tycho release that supports Java 25?

[akurtakov]

There is no ecj release with support for Java 25 so Tycho release with full builtin Java 25 support will not happen before there is such ecj release (scheduled for 10/12/2025 as per https://github.com/eclipse-simrel/.github/blob/main/wiki/SimRel/2025-12.md) and Tycho usually needs some time to integrate the new release .
Targetting Java 25 using javac (example here https://github.com/eclipse-shellwax/shellwax/blob/d515a4aa8db099aa332ec81bf1ecfecebb4ec9b7/pom.xml#L118 ) might happen earlier but it is blocked by
#5446 .

[selundqma]

I could build with Java 25 using Tycho 5.0.1 and changing from BREE (Bundle-RequiredExecutionEnvironment: JavaSE-25) to osgi.ee capability (Require-Capability: osgi.ee;filter:="(&(osgi.ee=JavaSE)(version=25))") in every MANIFEST.MF file. Also specified <compilerId/>javac</compilerId> for the tycho-compiler-plugin and set <maven.compiler.release>25</maven.compiler.release>. Hope it works for you too. Now we are of course waiting for the "real" deal and use the ECJ.

[thomasa299792]

Eclipse 2025_12 was released today, with support for Java 25.

[akurtakov]

Please try 5.0.2-SNAPSHOT or 6.0.0-SNAPSHOT and report whether Java 25 works fine for you.

[selundqma]

@akurtakov I could build without both the "javac" flag and maven.compiler.release set to 25 with 5.0.2-SNAPSHOT! Thanks! Looking forward to the release version of it later on.

[laeubi]

bnd lib was now updated so that the workaround with

changing from BREE (Bundle-RequiredExecutionEnvironment: JavaSE-25) to osgi.ee capability (Require-Capability: osgi.ee;filter:="(&(osgi.ee=JavaSE)(version=25))") in every MANIFEST.MF file

is no longer necessary see

• Bump bnd.version from 7.1.0 to 7.2.0 #5736

We are waiting for approval of the new jars right now.

[herglotzmarco]

I can confirm the combination of 5.0.2-SNAPSHOT and Require-Capability in addition to BREE works for our application. Thanks for the hints!
I guess the BREE workaround can be removed after the PR mentioned by @laeubi is merged, however we still have to wait for the new tycho release. Is there already a timeplan for the official release of 5.0.2?

[laeubi]

I rebased the PR and if no further issues occur it should be available in a few hours. Regarding the release there is no special schedule we mostly do them on demand.As all the dependency updates are settled I likely will make a release in the next weeks somehow if nothing else prevents us from doing so.

[herglotzmarco]

I likely will make a release in the next weeks somehow if nothing else prevents us from doing so.

Love to hear that! Thanks for the quick answer

[laeubi]

The bndlib upgrade is merged, please test the new snapshots if the problem is gone now!
I'll prepare a release the next days if no more issues will be discovered with that.

[herglotzmarco]

Tested the updated snapshots: Build runs just fine without Require-Capability now 👍

[alexsuter]

[ERROR] Failed to execute goal org.eclipse.tycho:tycho-compiler-plugin:5.0.1:compile (default-compile) on project ch.ivyteam.util.api: Fatal error compiling: target level should be in '1.8','9'...'24' (or '8.0'..'24.0'): 25 -> [Help 1]
org.apache.maven.lifecycle.LifecycleExecutionException: Failed to execute goal org.eclipse.tycho:tycho-compiler-plugin:5.0.1:compile (default-compile) on project ch.ivyteam.util.api: Fatal error compiling
    at org.apache.maven.lifecycle.internal.MojoExecutor.doExecute2 (MojoExecutor.java:333)
    at org.apache.maven.lifecycle.internal.MojoExecutor.doExecute (MojoExecutor.java:316)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:212)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:174)
    at org.apache.maven.lifecycle.internal.MojoExecutor.access$000 (MojoExecutor.java:75)
    at org.apache.maven.lifecycle.internal.MojoExecutor$1.run (MojoExecutor.java:162)
    at org.apache.maven.plugin.DefaultMojosExecutionStrategy.execute (DefaultMojosExecutionStrategy.java:39)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:159)
    at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject (LifecycleModuleBuilder.java:105)
    at org.apache.maven.lifecycle.internal.builder.multithreaded.MultiThreadedBuilder$1.call (MultiThreadedBuilder.java:193)
    at org.apache.maven.lifecycle.internal.builder.multithreaded.MultiThreadedBuilder$1.call (MultiThreadedBuilder.java:180)
    at java.util.concurrent.FutureTask.run (FutureTask.java:328)
    at java.util.concurrent.Executors$RunnableAdapter.call (Executors.java:545)
    at java.util.concurrent.FutureTask.run (FutureTask.java:328)
    at java.util.concurrent.ThreadPoolExecutor.runWorker (ThreadPoolExecutor.java:1090)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run (ThreadPoolExecutor.java:614)
    at java.lang.Thread.run (Thread.java:1474)

I guess tycho needs to be updated, right?

[laeubi]

As mentioned you need to use the current snapshot (that will be released in the next days) to test.