quarkusio/quarkus · error · GradleException

Failed to add extensions + getExtensionsToAdd()

Error message

Failed to add extensions + getExtensionsToAdd()

What it means

Thrown by QuarkusAddExtension.addExtension() as a wrapper when executing the AddExtensions command (which modifies the build file to add extension dependencies) fails for any reason. The original exception is attached as the cause; the message includes the extensions that were requested.

Source

Thrown at devtools/gradle/gradle-application-plugin/src/main/java/io/quarkus/gradle/tasks/QuarkusAddExtension.java:49

    @Input
    public List<String> getExtensionsToAdd() {
        return extensionsToAdd;
    }

    @TaskAction
    public void addExtension() {
        Set<String> extensionsSet = getExtensionsToAdd()
                .stream()
                .flatMap(ext -> stream(ext.split(",")))
                .map(String::trim)
                .collect(toSet());

        try {
            AddExtensions addExtensions = new AddExtensions(getQuarkusProject(false))
                    .extensions(extensionsSet);
            addExtensions.execute();
        } catch (Exception e) {
            throw new GradleException("Failed to add extensions " + getExtensionsToAdd(), e);
        }
    }
}

View on GitHub (pinned to e1c734241f)

Solutions

1. Inspect the 'Caused by' in the stack trace to see the underlying failure
2. Add the dependency manually in build.gradle(.kts), e.g. implementation("io.quarkus:quarkus-cache")
3. Verify the extension name/coordinates are valid (use the Quarkus registry) and that build files are writable

Example fix

// before: gradle addExtension --extensions=quarkus-not-a-real-ext  -> GradleException
// after: add manually in build.gradle
dependencies { implementation("io.quarkus:quarkus-cache") }

// ensure extension name is valid before running the task
if (!extName.matches(Regex("quarkus-[a-z0-9-]+")))
  throw IllegalArgumentException("Invalid extension id: $extName")

task 'addExtension' fails with GradleException('Failed to add extensions ...'):
// read e.cause (or the 'Caused by:' block) to decide between
// manual dependency add vs fixing file permissions/coordinates

When it happens

Trigger: Running gradle addExtension --extensions=... when the build script cannot be parsed/modified (unsupported build script format, version catalog or unusual dependency syntax, read-only files, or an invalid extension coordinates string).

Common situations: Using addExtension in projects with build.gradle.kts constructs the tool cannot rewrite; offline/invalid artifact coordinates causing resolution failure; permission problems on build files in CI containers.

Related errors

• Failed to resolve ${appArtifact}
• Requested artifact ${appArtifact} does not match project ${g
• No platforms detected in the project
• Failed to determine the Quarkus core version for the project
• Failed to configure ${taskPath}: sourceSet ${sourceSet} has

AI-assisted analysis of quarkusio/quarkus@e1c734241f (2026-09-05). Data as JSON: /api/errors/a15e7823848e1001. Report an issue: GitHub.