quarkusio/quarkus · error · CodeGenException

e.getMessage() (rethrow of code generation failure)

Error message

e.getMessage() (rethrow of code generation failure)

What it means

extractProtosFromArtifact catches its own GrpcCodeGenException and rethrows it as a generic io.quarkus.deployment.CodeGenException with the same message, preserving the cause. This is the wrapping boundary developers actually see in build logs; the root message will be one of the more specific 'Failed to create directory' or 'Failed to extract proto file' errors.

Source

Thrown at extensions/grpc/codegen/src/main/java/io/quarkus/grpc/codegen/GrpcCodeGen.java:436

                                throw new GrpcCodeGenException("Failed to create directory: " + protoOutputDir, e);
                            }
                            Path outPath = protoOutputDir.resolve(strippedPathStr);
                            try {
                                Files.createDirectories(outPath.getParent());
                                if (isDependency) {
                                    copySanitizedProtoFile(artifact, path, outPath);
                                } else {
                                    Files.copy(path, outPath, StandardCopyOption.REPLACE_EXISTING);
                                }
                                protoFiles.add(outPath);
                            } catch (IOException e) {
                                throw new GrpcCodeGenException("Failed to extract proto file" + path + " to target: "
                                        + outPath, e);
                            }
                        }
                    });
        } catch (GrpcCodeGenException e) {
            throw new CodeGenException(e.getMessage(), e);
        }
    }

    private static String stripProtoPrefix(String relativePathStr) {
        if (relativePathStr.startsWith(SRC_MAIN_PROTO_DIR)) {
            return relativePathStr.substring(SRC_MAIN_PROTO_DIR.length());
        }
        if (relativePathStr.startsWith(SRC_TEST_PROTO_DIR)) {
            return relativePathStr.substring(SRC_TEST_PROTO_DIR.length());
        }
        if (relativePathStr.startsWith(PROTO_DIR)) {
            return relativePathStr.substring(PROTO_DIR.length());
        }
        return relativePathStr;
    }

    private static Path getProtoOutputDir(Path workDir, ResolvedDependency artifact) {
        String uniqueName = artifact.getGroupId() + ":" + artifact.getArtifactId();

View on GitHub (pinned to e1c734241f)

Solutions

1. Read the caused-by chain: the root GrpcCodeGenException/IOException names the real problem (permissions, missing file, disk)
2. Run mvn clean / gradle clean and rebuild to clear stale generated output
3. Fix the underlying IO condition (writable target dir, intact artifact JAR) rather than the CodeGenException itself
4. If it reproduces on a good checkout, pin/refresh the dependency containing the proto files

try {
    quarkusBuild.perform();
} catch (CodeGenException e) {
    // always inspect the cause chain — this exception wraps a GrpcCodeGenException/IOException
    Throwable root = e;
    while (root.getCause() != null) root = root.getCause();
    log.error("gRPC codegen failed, root cause: " + root.getMessage(), e);
}

When it happens

Trigger: Any failure inside proto extraction (directory creation or file copy during scanning of dependency protos) surfaces as this CodeGenException during the generate-code phase of quarkus:dev, mvn compile, or a Quarkus build.

Common situations: Same underlying causes as the wrapped errors: unwritable build directory, locked or corrupted dependency JARs, disk space, long Windows paths — plus confusing stack traces where the top-level CodeGenException hides the IO detail.

Related errors

• Failed to generate Java classes from proto files: %s to %s w
• Failed to generate java files from proto file in " + inputDi
• Failed to create directory: " + protoOutputDir
• Failed to extract proto file" + path + " to target: " + outP
• Failed to find ${location} among dependencies

AI-assisted analysis of quarkusio/quarkus@e1c734241f (2026-09-05). Data as JSON: /api/errors/4cedf67a1068664d. Report an issue: GitHub.