quarkusio/quarkus · error · GradleException

Failed to run

Error message

Failed to run

What it means

The entire body of QuarkusDev.startDev — preparing arguments, writing config, and launching the dev-mode forked JVM via ExecOperations — is wrapped in a try/catch that rethrows any Exception as a GradleException('Failed to run', e). It is a generic wrapper; the real cause is the chained exception, which must be read from the full stack trace.

Source

Thrown at devtools/gradle/gradle-application-plugin/src/main/java/io/quarkus/gradle/tasks/QuarkusDev.java:391

            if (outputFile == null) {
                getExecOperations().exec(action -> {
                    action.commandLine(runner.getArguments()).workingDir(getWorkingDirectory().get());
                    action.environment(getEnvVars());
                    action.setStandardInput(System.in)
                            .setErrorOutput(System.out)
                            .setStandardOutput(System.out);
                });
            } else {
                try (BufferedWriter is = Files.newBufferedWriter(Paths.get(outputFile))) {
                    for (String i : runner.getArguments()) {
                        is.write(i);
                        is.newLine();
                    }
                }
            }

        } catch (Exception e) {
            throw new GradleException("Failed to run", e);
        } finally {
            analyticsService.close();
        }
    }

    private boolean sourcesExist() {
        final Set<FileSystemLocation> srcDirLocations = mainSourceSet.getAllJava().getSourceDirectories().getElements().get();
        for (FileSystemLocation srcDirLocation : srcDirLocations) {
            final File srcDir = srcDirLocation.getAsFile();
            if (srcDir.exists() && srcDir.isDirectory()) {
                final File[] files = srcDir.listFiles();
                if (files != null && files.length > 0) {
                    return true;
                }
            }
        }
        return false;
    }

View on GitHub (pinned to e1c734241f)

Solutions

1. Read the 'Caused by' chain in the stack trace to find the real failure and fix that first
2. Run ./gradlew quarkusDev --stacktrace --info for the full cause and context
3. Verify JAVA_HOME/java toolchain availability and that no other process holds the dev-mode port
4. Delete build output (./gradlew clean) to clear stale generated files, then retry

Example fix

// diagnose, don't patch:
./gradlew quarkusDev --stacktrace --info
// then fix the underlying 'Caused by' (e.g. free port 8080:
// lsof -i :8080 && kill <pid>)

// always inspect the cause chain, not the wrapper message
try {
    ./gradlew quarkusDev --stacktrace --info
} catch (...) { /* parse 'Caused by:' entries and fix the root cause */ }

When it happens

Trigger: Any exception while starting dev mode: failure to resolve/fork the dev-mode process, malformed configuration written for the application, IO errors on generated files, or a thrown error during analytics prompt handling.

Common situations: Invalid quarkus.* properties that dev mode cannot serialize; port conflicts or missing java toolchain when forking; corrupted application model; failure downloading the dev-mode artifacts listed just above this wrapper in the log.

Related errors

• At least one source directory (e.g. src/main/java, src/main/
• The project has no output yet, this should not happen as bui
• Unable to deserialize the dev mode context. Does the Quarkus
• Hot deployment of the application is not supported when upda
• remote-dev can only be used with mutable applications i.e. u

AI-assisted analysis of quarkusio/quarkus@e1c734241f (2026-09-05). Data as JSON: /api/errors/d1a8fcaadd96a4b8. Report an issue: GitHub.