junit-team/junit5 · error · UncheckedIOException

Failed to close XML events file

Error message

Failed to close XML events file

What it means

Thrown by OpenTestReportGeneratingListener.testPlanExecutionFinished() as an UncheckedIOException when DocumentWriter.close() raises IOException while finalising the events XML. Occurs at the end of a test plan execution; the writer is reset to noop in a finally block but the IOException is rethrown.

Source

Thrown at junit-platform-reporting/src/main/java/org/junit/platform/reporting/open/xml/OpenTestReportGeneratingListener.java:222

		git.getOriginUrl() //
				.ifPresent(
					gitUrl -> infrastructure.append(repository(), repository -> repository.withOriginUrl(gitUrl)));
		git.getBranch() //
				.ifPresent(branch -> infrastructure.append(branch(branch)));
		git.getCommitHash() //
				.ifPresent(gitCommitHash -> infrastructure.append(commit(gitCommitHash)));
		git.getStatus() //
				.ifPresent(statusOutput -> infrastructure.append(status(statusOutput),
					status -> status.withClean(statusOutput.isEmpty())));
	}

	@Override
	public void testPlanExecutionFinished(TestPlan testPlan) {
		try {
			eventsFileWriter.close();
		}
		catch (IOException e) {
			throw new UncheckedIOException("Failed to close XML events file", e);
		}
		finally {
			eventsFileWriter = DocumentWriter.noop();
		}
	}

	@Override
	public void executionSkipped(TestIdentifier testIdentifier, String reason) {
		String id = String.valueOf(idCounter.incrementAndGet());
		reportStarted(testIdentifier, id);
		eventsFileWriter.append(finished(id, Instant.now()), //
			finished -> finished.append(result(Result.Status.SKIPPED), result -> {
				if (isNotBlank(reason)) {
					result.append(reason(reason));
				}
			}));
	}

View on GitHub (pinned to 956246301e)

Solutions

1. Ensure the output filesystem has capacity and remains mounted for the entire run.
2. In socket mode, keep the server connected until testPlanExecutionFinished completes.
3. Inspect the wrapped IOException for the specific failure (broken pipe, no space, etc.).
4. Disable XML reporting if the environment cannot guarantee a clean close.

Example fix

// before: disk fills during run, close() throws UncheckedIOException

// after: ensure adequate disk space; or disable reporting
junit.platform.reporting.open.xml.enabled = false

// Ensure the output medium stays healthy for the whole run
long free = outputDir.toFile().getUsableSpace();
if (free < MIN_FREE_BYTES) throw new IllegalStateException("low disk: " + free);

static boolean writerLikelyCloseable(DocumentWriter<?> w) {
    try { w.flush(); return true; } catch (IOException e) { return false; }
}

try {
    eventsFileWriter.close();
} catch (IOException e) {
    // log and continue; the report may be partial but the run need not abort
    log.warn("Failed to close XML events file: {}", e.getMessage());
} finally {
    eventsFileWriter = DocumentWriter.noop();
}

When it happens

Trigger: XML reporting was enabled and the events file writer fails to flush/close - e.g. the underlying file/stream was closed externally, the socket (in socket mode) dropped, or the filesystem failed the final write.

Common situations: Disk filled during the run. Socket server disconnected mid-stream in socket mode. File deleted or FS unmounted before close. Process received a signal that left the writer half-open.

Related errors

• Failed to create XML events file
• Failed to start process
• Failed to initialize XML events writer
• Could not read color palette properties
• Could not open color palette properties file

AI-assisted analysis of junit-team/junit5@956246301e (2026-08-04). Data as JSON: /data/errors/21fe7ff0cb4a80b6.json. Report an issue: GitHub.