quarkusio/quarkus · error · UnsupportedOperationException

This operation is only supported for Gradle projects

Error message

This operation is only supported for Gradle projects

What it means

UpgradeGradlePluginOperation.single() generates rewrite recipe operations for upgrading a Gradle plugin version. For a GRADLE or GRADLE_KOTLIN_DSL project it returns the UpgradePluginVersion recipe parameters; for any other build tool it throws UnsupportedOperationException("This operation is only supported for Gradle projects"), since upgrading Gradle plugin versions has no meaning in Maven builds.

Source

Thrown at independent-projects/tools/devtools-common/src/main/java/io/quarkus/devtools/project/update/rewrite/operations/UpgradeGradlePluginOperation.java:27

    private final String pluginIdPattern;
    private final String newVersion;

    public UpgradeGradlePluginOperation(String pluginIdPattern, String newVersion) {
        this.pluginIdPattern = pluginIdPattern;
        this.newVersion = newVersion;
    }

    @Override
    public Map<String, Object> single(BuildTool buildTool) {
        switch (buildTool) {
            case GRADLE_KOTLIN_DSL:
            case GRADLE:
                return Map.of(
                        "org.openrewrite.gradle.plugins.UpgradePluginVersion",
                        Map.of("pluginIdPattern", pluginIdPattern, "newVersion", newVersion));
            default:
                throw new UnsupportedOperationException("This operation is only supported for Gradle projects");
        }
    }
}

View on GitHub (pinned to e1c734241f)

Solutions

1. Only apply UpgradeGradlePluginOperation to Gradle projects — gate it on BuildTool.GRADLE / GRADLE_KOTLIN_DSL.
2. For Maven projects, use the Maven rewrite plugin version upgrade operation instead.
3. Verify the project's detected build tool before running plugin upgrade operations.

Example fix

// before
new UpgradeGradlePluginOperation(pluginIdPattern, newVersion).single(BuildTool.MAVEN, ...);
// after
if (buildTool == BuildTool.GRADLE || buildTool == BuildTool.GRADLE_KOTLIN_DSL) {
    new UpgradeGradlePluginOperation(pluginIdPattern, newVersion).single(buildTool, ...);
}

if (buildTool != BuildTool.GRADLE && buildTool != BuildTool.GRADLE_KOTLIN_DSL) {
    return; // skip Gradle plugin upgrade operation for non-Gradle projects
}

static boolean isGradle(BuildTool t) {
    return t == BuildTool.GRADLE || t == BuildTool.GRADLE_KOTLIN_DSL;
}

try {
    op.single(buildTool, ...);
} catch (UnsupportedOperationException e) {
    log.warn("Skipping Gradle plugin upgrade: " + e.getMessage());
}

When it happens

Trigger: Calling UpgradeGradlePluginOperation.single() with a BuildTool other than GRADLE or GRADLE_KOTLIN_DSL — e.g. a MAVEN project — hits the default branch. Occurs when a build-tool-agnostic update flow applies the Gradle-plugin upgrade operation indiscriminately.

Common situations: Running a custom update recipe that includes the UpgradePluginVersion operation against a Maven project; a script that iterates operations without filtering by build tool; misdetected build tool when a Gradle plugin upgrade is requested on a Maven-only codebase.

Related errors

• Quarkus Gradle plugins require Gradle
• You are trying to create a Maven project in a directory that
• You are trying to create gradle Project in a directory that
• This feature is not yet implemented outside of the Gradle Pl
• ${buildTool} is not supported yet

AI-assisted analysis of quarkusio/quarkus@e1c734241f (2026-09-05). Data as JSON: /api/errors/453f259db4064eb2. Report an issue: GitHub.