-deprecation flag ignores deprecated Java annotation

[gaeljw]

Compiler version

3.7.3

Minimized code

https://github.com/gaeljw/scala3_deprecated_java_annotation (uses SBT but the code itself is minimized)

For the record, here's the minimal example that I'm using in this repo:

import io.cucumber.junit.CucumberOptions // <-- this annotation is Java and Deprecated

@CucumberOptions(
  features = Array("test/features/internal")
)
class CucumberRunner {
}

package io.cucumber.junit;

import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

@Deprecated
@Retention(RetentionPolicy.RUNTIME)
@Target({ ElementType.TYPE })
public @interface CucumberOptions {
    String[] features() default {};
}

When compiling with -deprecation (and -Werror) flags, no error occurs in Scala 3 whereas it does in Scala 2.

The linked repository contains both the Scala 2 and Scala 3 project examples.

Output

Scala 2:

(cd testscala2 && sbt "Test / compile")
[info] welcome to sbt 1.11.6 (Red Hat, Inc. Java 21.0.8)
[info] loading settings for project global-plugins from plugins.sbt...
[info] loading global plugins from /home/jourdang/.sbt/1.0/plugins
[info] loading project definition from /tmp/testwarndeprecatedjavaannotation/testscala2/project
[info] loading settings for project root from build.sbt...
[info] set current project to testscala2 (in build file:/tmp/testwarndeprecatedjavaannotation/testscala2/)
[info] compiling 1 Scala source to /tmp/testwarndeprecatedjavaannotation/testscala2/target/scala-2.13/test-classes ...
[error] /tmp/testwarndeprecatedjavaannotation/testscala2/src/test/scala/example/CucumberRunner.scala:9:7: Java annotation CucumberOptions in package junit is deprecated
[error] class CucumberRunner {
[error]       ^
[error] one error found
[error] (Test / compileIncremental) Compilation failed
[error] Total time: 2 s, completed 11 sept. 2025, 18:05:08

Scala 3: no error.

(cd testscala3 && sbt "Test / compile")                                          
[info] welcome to sbt 1.11.6 (Red Hat, Inc. Java 21.0.8)
[info] loading settings for project global-plugins from plugins.sbt...
[info] loading global plugins from /home/jourdang/.sbt/1.0/plugins
[info] loading project definition from /tmp/testwarndeprecatedjavaannotation/testscala3/project
[info] loading settings for project root from build.sbt...
[info] set current project to testscala3 (in build file:/tmp/testwarndeprecatedjavaannotation/testscala3/)
[success] Total time: 1 s, completed 11 sept. 2025, 18:04:36

Expectation

An error should also be raised in Scala 3.

[hamzaremmal]

We also don't report for scala deprecations. See #23905.

[gaeljw]

Good catch @hamzaremmal , I didn't think to check with a Scala annotation! 👍