quarkusio/quarkus · error · MojoExecutionException

Failed to initialize file output writer

Error message

Failed to initialize file output writer

What it means

DependencyListMojo can write the resolved dependency list to a file (outputFile). Before logging, it creates parent directories and opens a BufferedWriter, applying APPEND when appendOutput is set and the file exists. Any IOException while doing so is wrapped in a MojoExecutionException 'Failed to initialize file output writer', aborting the mojo before any dependency output is produced.

Source

Thrown at devtools/maven/src/main/java/io/quarkus/maven/DependencyListMojo.java:144

    protected MavenArtifactResolver resolver;

    @Override
    public void execute() throws MojoExecutionException, MojoFailureException {

        BufferedWriter writer = null;
        final Consumer<String> log;
        if (outputFile == null) {
            log = s -> getLog().info(s);
        } else {
            final BufferedWriter bw;
            try {
                Files.createDirectories(outputFile.toPath().getParent());
                final OpenOption[] openOptions = appendOutput && outputFile.exists()
                        ? new OpenOption[] { StandardOpenOption.APPEND }
                        : new OpenOption[0];
                bw = writer = Files.newBufferedWriter(outputFile.toPath(), openOptions);
            } catch (IOException e) {
                throw new MojoExecutionException("Failed to initialize file output writer", e);
            }
            log = s -> {
                try {
                    bw.write(s);
                    bw.newLine();
                } catch (IOException e) {
                    throw new RuntimeException("Failed to log the dependency list to a file", e);
                }
            };
        }
        try {
            logDependencies(log);
        } finally {
            if (writer != null) {
                try {
                    writer.close();
                } catch (IOException e) {
                    getLog().debug("Failed to close the output file", e);

View on GitHub (pinned to e1c734241f)

Solutions

1. Check and fix filesystem permissions on the output file's parent directory
2. Ensure the outputFile path is valid and its parent is a directory, not a file
3. Free disk space if the disk is full
4. Point -DoutputFile (or pom configuration) to a writable location

Example fix

// before
mvn quarkus:dependency-list -DoutputFile=/root/protected/deps.txt
// after
mvn quarkus:dependency-list -DoutputFile=${project.build.directory}/deps.txt

// Pre-check output file writability before running the mojo
java.nio.file.Path out = java.nio.file.Path.of(outputFile);
java.nio.file.Path parent = out.toAbsolutePath().getParent();
if (parent == null || !java.nio.file.Files.isDirectory(parent) && !parent.toFile().mkdirs()) {
    throw new IllegalStateException("Cannot create directory: " + parent);
}
if (!java.nio.file.Files.isWritable(parent)) {
    throw new IllegalStateException("Directory not writable: " + parent);
}
if (java.nio.file.Files.exists(out) && !java.nio.file.Files.isWritable(out)) {
    throw new IllegalStateException("Output file not writable: " + out);
}

try {
    mvn quarkus:dependency-list -DoutputFile=target/deps.txt;
} catch (MojoExecutionException e) {
    if ("Failed to initialize file output writer".equals(e.getMessage())) {
        // inspect e.getCause() (IOException): fix path/permissions and retry
        Throwable cause = e.getCause();
    }
}

When it happens

Trigger: Running mvn quarkus:dependency-list (or related goal) with output file configuration where Files.newBufferedWriter or Files.createDirectories throws IOException — e.g. unwritable path, parent path is a file, or disk/permission problems.

Common situations: outputFile points to a read-only directory or outside the project; parent path exists as a regular file; running in CI with restricted filesystem permissions; container/user mismatch on mounted volumes; disk full.

Understand the failure class

Background: "Permission denied" / "Failed to write" file errors: why a library can't write its files to disk (EACCES, EPERM, ENOSPC) and how to fix them — this error's family across 43 libraries.

Related errors

• Failed to log the dependency list to a file
• Failed to initialize file output writer
• Failed to log the dependency tree to a file
• Unable to write quarkus native image agent caller filter to
• Failed to create the output dir ${projectFile}

AI-assisted analysis of quarkusio/quarkus@e1c734241f (2026-09-05). Data as JSON: /api/errors/1aa668a0e61e3a34. Report an issue: GitHub.