kestra-io/kestra · error · IllegalArgumentException

Cannot create a working directory file with a null path

Error message

Cannot create a working directory file with a null path

What it means

Thrown by `LocalWorkingDir.putFile(Path, InputStream, ...)` when the `path` argument is null. `putFile` writes a stream to a path inside the working directory; a null path is a programming error. Thrown as `IllegalArgumentException` before any filesystem operation.

Source

Thrown at core/src/main/java/io/kestra/core/runners/LocalWorkingDir.java:194

        return newFilePath;
    }

    /**
     * {@inheritDoc}
     **/
    @Override
    public Path putFile(Path path, InputStream inputStream) throws IOException {
        return putFile(path, inputStream, FileExistComportment.OVERWRITE);
    }

    /**
     * {@inheritDoc}
     **/
    @Override
    public Path putFile(Path path, InputStream inputStream, FileExistComportment comportment) throws IOException {
        if (path == null) {
            throw new IllegalArgumentException("Cannot create a working directory file with a null path");
        }
        if (inputStream == null) {
            throw new IllegalArgumentException("Cannot create a working directory file with an empty inputStream");
        }
        Path newFilePath = this.resolve(path);
        Files.createDirectories(newFilePath.getParent());

        if (Files.exists(newFilePath)) {
            switch (comportment) {
                case OVERWRITE -> {
                    log.info("File {} already exist. It will be overwritten", newFilePath);
                    copyFile(inputStream, newFilePath);
                }
                case FAIL -> throw new FileAlreadyExistsException("File " + newFilePath + " already exist");
                case WARN -> log.warn("File {} already exist. It will be ignore", newFilePath);
                case IGNORE -> {
                }
            }

View on GitHub (pinned to 823fada927)

Solutions

1. Ensure the path is non-null before calling `putFile`; derive it from a validated filename.
2. Use `createFile(filename, stream)` when you have a name rather than a Path.
3. Add a null-check at the call site with a clear error.

Example fix

// before
Path target = computedPath; // null
workingDir.putFile(target, in);

// after
if (target == null) throw new IllegalStateException("target path is null");
workingDir.putFile(target, in);

if (path == null) {
    throw new IllegalArgumentException("Cannot putFile: path is null");
}
return workingDir.putFile(path, inputStream);

static boolean hasPath(Path p) { return p != null; }

When it happens

Trigger: Calling `workingDir.putFile(null, stream)` or `putFile(null, stream, comportment)`. Typically the path is computed from a variable/expression that evaluated to null.

Common situations: A filename derived from a Pebble expression that returned null; a refactor that changed the type flowing into `putFile`; test code passing a literal null.

Related errors

• Cannot create a working directory file with a null or empty
• Cannot create a working directory file with an empty inputSt
• The path to resolve must be a relative path inside the curre
• File {} already exist
• Invalid flow path

AI-assisted analysis of kestra-io/kestra@823fada927 (2026-08-14). Data as JSON: /api/errors/be256c55f443b7df. Report an issue: GitHub.