What causes "Could not read DOM from [ ]" in quarkusio/quarkus?

Verify the pom path exists and is a regular file before transforming

quarkusio/quarkus · error · RuntimeException

Could not read DOM from [<path>]

Error message

Could not read DOM from [<path>]

What it means

PomTransformer.transform(Collection<Transformation>) reads the pom at the configured path with Files.readString inside a supplier; any IOException is rethrown as RuntimeException 'Could not read DOM from [<path>]'. It means the transformer could not load the pom source text to build its DOM.

Source

Thrown at independent-projects/tools/devtools-common/src/main/java/io/quarkus/maven/utilities/PomTransformer.java:85

     *
     * @param transformations the {@link Transformation}s to apply
     */
    public void transform(Transformation... transformations) {
        transform(Arrays.asList(transformations));
    }

    /**
     * Loads the document under {@link #path}, applies the given {@code transformations}, mitigates the formatting
     * issues caused by {@link Transformer} and finally stores the document back to the file under {@link #path}.
     *
     * @param transformations the {@link Transformation}s to apply
     */
    public void transform(Collection<Transformation> transformations) {
        transform(transformations, path, () -> {
            try {
                return Files.readString(path, charset);
            } catch (IOException e) {
                throw new RuntimeException(String.format("Could not read DOM from [%s]", path), e);
            }
        }, xml -> {
            try {
                Files.write(path, xml.getBytes(charset));
            } catch (IOException e) {
                throw new RuntimeException(String.format("Could not write DOM from [%s]", path), e);
            }
        });
    }

    static void transform(Collection<Transformation> edits, Path path, Supplier<String> source,
            Consumer<String> outConsumer) {
        final String src = source.get();

        final Document document;
        try {
            final DOMResult domResult = new DOMResult();
            TransformerFactory.newInstance().newTransformer()

View on GitHub (pinned to e1c734241f)

Solutions

Verify the pom path exists and is a regular file before transforming
Check read permissions for the current user/process
Run the command from the directory containing pom.xml or pass the correct -f/--pom path
Close other processes holding a lock on the file

Example fix

// before
new PomTransformer(pomPath, StandardCharsets.UTF_8, NodeSupplier.lastChildOf(null)).transform(edits); // path missing
// after
if (!Files.isRegularFile(pomPath)) {
    throw new IllegalStateException("pom not found: " + pomPath);
}
new PomTransformer(pomPath, StandardCharsets.UTF_8, NodeSupplier.lastChildOf(null)).transform(edits);

Defensive patterns

Strategy: validation

Validate before calling

if (!Files.isRegularFile(path)) {
    throw new IllegalStateException("Expected pom file not found: " + path);
}
if (!Files.isReadable(path)) {
    throw new IllegalStateException("pom not readable: " + path);
}

Try / catch

try {
    transformer.transform(edits);
} catch (RuntimeException e) {
    if (e.getMessage() != null && e.getMessage().startsWith("Could not read DOM")) {
        throw new IllegalStateException("Pom unreadable at " + path, e.getCause());
    }
    throw e;
}

Prevention

Check file existence/readability before constructing the transformer
Run Maven goals from the project root or pass an explicit pom path
Avoid holding the pom open in tools that lock it during transformation
Verify the working directory matches expectations in scripts and IDEs

When it happens

Trigger: Calling pomTransformer.transform(...) when the pom file does not exist, is unreadable (permissions), or the path is a directory; the charset-decoded read fails with IOException.

Common situations: Running an extension/dev-mode goal in a project without a pom.xml at the expected location, wrong working directory, file locked by another process, or permissions changed after construction.

Related errors

AI-assisted analysis of quarkusio/quarkus@e1c734241f (2026-09-05). Data as JSON: /api/errors/8e960f6b98db534c. Report an issue: GitHub.