quarkusio/quarkus · error · GradleException

Failed to delete file:

Error message

Failed to delete file: 

What it means

CustomFileSystemOperations.deleteFileIfExists wraps Files.deleteIfExists; any IOException (e.g. file locked or in use) is rethrown as GradleException 'Failed to delete file: <path>'. It's used when the copy/sync operation must remove an existing destination file that is not writable before overwriting it.

Source

Thrown at devtools/gradle/gradle-application-plugin/src/main/java/io/quarkus/gradle/util/CustomFileSystemOperations.java:167

     * Deletes files and directories.
     *
     * @param action the delete action configuration
     * @return the result of the delete operation
     */
    public WorkResult delete(Action<? super DeleteSpec> action) {
        return getFs().delete(action);
    }

    /**
     * Deletes a file if it exists.
     *
     * @param file the file to delete
     */
    public static void deleteFileIfExists(Path file) {
        try {
            Files.deleteIfExists(file);
        } catch (IOException e) {
            throw new GradleException("Failed to delete file: " + file, e);
        }
    }

    private static void configureCopyOrSyncOperation(CopySpec copy, CopySyncConfiguration config,
            List<CopiedFileMetadata> copiedFilesMetadata) {
        // iterate over sources to be able to pass each source path to the TimestampPreservingCopyAction
        for (Path src : config.sources) {
            copy.from(src, spec -> spec.eachFile(
                    new TimestampPreservingCopyAction(
                            src,
                            config.destination,
                            copiedFilesMetadata)));
        }

        copy.into(config.destination);

        if (!config.includes.isEmpty()) {
            copy.include(config.includes);

View on GitHub (pinned to e1c734241f)

Solutions

1. Close processes holding the file (stop the running Quarkus app, dev mode, IDE indexing) then retry.
2. Check and fix permissions: ensure the destination directory is writable by the build user.
3. On Windows, reboot or use handle.exe to find the locker; exclude the build dir from antivirus.
4. Free the mount if the destination is on a read-only filesystem.

Path dest = ...;
File dir = dest.getParent().toFile();
if (Files.exists(dest) && !Files.isWritable(dest)) throw new IllegalStateException("dest not writable: " + dest);
if (!dir.canWrite()) throw new IllegalStateException("dest dir not writable: " + dir);

try {
    ./gradlew build
} catch (GradleException e) {
    if (e.getMessage().startsWith("Failed to delete file:")) {
        Path locked = Paths.get(e.getMessage().replace("Failed to delete file: ", ""));
        // stop the process holding it, chmod, or clear read-only mount, then retry
    }
}

When it happens

Trigger: Executing a Quarkus copy/sync Gradle operation where an existing destination file must be deleted but Files.deleteIfExists throws IOException — destination file is locked by another process (IDE, running app, antivirus on Windows), read-only filesystem, or insufficient permissions on the parent directory.

Common situations: Windows: destination jar/classes locked by a running application or file indexer; Linux: read-only volume mount; destination inside a directory owned by another user; a previously failed build left immutable files.

Related errors

• Failed to collect project's classes in a temporary dir
• Failed to write Quarkus build configuration settings
• Failed to get source file mtime for
• Failed to create output directory for generated sources: %s
• IOException (wrapped)

AI-assisted analysis of quarkusio/quarkus@e1c734241f (2026-09-05). Data as JSON: /api/errors/5bb29a8fc53e2f88. Report an issue: GitHub.