quarkusio/quarkus · error · MojoExecutionException

You are trying to create a Maven project in a directory that

Error message

You are trying to create a Maven project in a directory that contains only Gradle build files.

What it means

When the create goal is asked to scaffold a Maven project (buildTool=maven) but the target directory contains only Gradle build files (build.gradle, settings.gradle, build.gradle.kts, settings.gradle.kts) and no pom.xml, the mojo refuses to proceed. Mixing build systems in one directory would produce a broken project, so it fails fast with this message.

Source

Thrown at devtools/maven/src/main/java/io/quarkus/maven/CreateProjectMojo.java:278

        if (buildToolEnum == null) {
            String validBuildTools = String.join(",",
                    Arrays.asList(BuildTool.values()).stream().map(BuildTool::toString).collect(Collectors.toList()));
            throw new IllegalArgumentException("Choose a valid build tool. Accepted values are: " + validBuildTools);
        }
        if (BuildTool.MAVEN.equals(buildToolEnum)) {
            if (pom != null && pom.isFile()) {
                try {
                    parentPomModel = MojoUtils.readPom(pom);
                    if (!"pom".equals(parentPomModel.getPackaging())) {
                        throw new MojoExecutionException(
                                "The parent project must have a packaging type of POM. Current packaging: "
                                        + parentPomModel.getPackaging());
                    }
                } catch (IOException e) {
                    throw new MojoExecutionException("Could not access parent pom.", e);
                }
            } else if (containsAtLeastOneGradleFile) {
                throw new MojoExecutionException(
                        "You are trying to create a Maven project in a directory that contains only Gradle build files.");
            }
        } else if (BuildTool.GRADLE.equals(buildToolEnum) || BuildTool.GRADLE_KOTLIN_DSL.equals(buildToolEnum)) {
            if (containsAtLeastOneGradleFile) {
                throw new MojoExecutionException("Adding subprojects to gradle projects is not implemented.");
            } else if (pom != null && pom.isFile()) {
                throw new MojoExecutionException(
                        "You are trying to create gradle project in a directory that contains only maven build files.");
            }
        }

        askTheUserForMissingValues();
        if (!DEFAULT_ARTIFACT_ID.equals(projectArtifactId) && !OK_ID.matcher(projectArtifactId).matches()) {
            throw new MojoExecutionException(String.format(BAD_IDENTIFIER, "artifactId", projectArtifactId));
        }
        if (!DEFAULT_GROUP_ID.equals(projectGroupId) && !OK_ID.matcher(projectGroupId).matches()) {
            throw new MojoExecutionException(String.format(BAD_IDENTIFIER, "groupId", projectGroupId));
        }

View on GitHub (pinned to e1c734241f)

Solutions

1. Run the goal with `-DbuildTool=gradle` (or gradle-kotlin-dsl) to match the directory, creating the project in a separate empty directory first
2. Create the project in a fresh empty directory and move it into a Gradle multi-module setup manually
3. Remove/rename the Gradle files if they are leftovers and a Maven project is genuinely intended

Example fix

// before
mvn quarkus:create -DbuildTool=maven   # run inside a Gradle-only dir
// after
mvn quarkus:create -DbuildTool=gradle  # in an empty parent directory

boolean gradleOnly = Stream.of("build.gradle","settings.gradle","build.gradle.kts","settings.gradle.kts")
        .anyMatch(n -> new File(dir, n).isFile());
boolean hasPom = new File(dir, "pom.xml").isFile();
if (buildTool.equals("maven") && gradleOnly && !hasPom) throw new IllegalStateException("Gradle-only directory");

try {
    runCreateGoal();
} catch (MojoExecutionException e) {
    if (e.getMessage().contains("directory that contains only Gradle build files")) {
        // rerun with -DbuildTool=gradle in an empty dir, or move to a Maven dir
    }
}

When it happens

Trigger: Running `mvn quarkus:create` (or create with -DbuildTool=maven) in a directory that has Gradle files but no pom.xml.

Common situations: Trying to add a Quarkus module inside an existing Gradle project using the Maven plugin, or cd-ing into a Gradle workspace directory out of habit.

Related errors

• You are trying to create gradle Project in a directory that
• Quarkus Gradle plugins require Gradle
• Could not resolve POM for
• Unable to add extensions
• Failed to initialize Maven artifact resolver

AI-assisted analysis of quarkusio/quarkus@e1c734241f (2026-09-05). Data as JSON: /api/errors/9026a3dde4b87ef5. Report an issue: GitHub.