shadow1ng/fscan · error

output config cannot be nil

Error message

output config cannot be nil

What it means

NewManager validates that a ManagerConfig pointer is supplied before constructing the output Manager. A nil config cannot describe an output path or format, so construction fails fast with 'output config cannot be nil'.

Source

Thrown at common/output/manager.go:21

import (
	"fmt"
	"os"
	"path/filepath"
	"sync"
)

// Manager 简化的输出管理器
type Manager struct {
	mu     sync.RWMutex
	config *ManagerConfig
	writer Writer
	closed bool
}

// NewManager 创建新的输出管理器
func NewManager(config *ManagerConfig) (*Manager, error) {
	if config == nil {
		return nil, fmt.Errorf("output config cannot be nil")
	}

	// 创建输出目录
	if err := createOutputDir(config.OutputPath); err != nil {
		return nil, err
	}

	manager := &Manager{
		config: config,
	}

	// 初始化写入器（内部会验证格式）
	if err := manager.initializeWriter(); err != nil {
		return nil, err
	}

	return manager, nil
}

View on GitHub (pinned to 95cc12e753)

Solutions

1. Allocate and populate a ManagerConfig before calling NewManager
2. Ensure your config loader returns a non-nil struct even on partial input
3. Add a nil check on the config source before constructing the manager

Example fix

// before
mgr, err := NewManager(nil)
// after
cfg := &ManagerConfig{OutputPath: "./out", Format: FormatJSON}
mgr, err := NewManager(cfg)

if cfg == nil {
    cfg = &ManagerConfig{OutputPath: defaultPath, Format: FormatJSON}
}
mgr, err := NewManager(cfg)

mgr, err := NewManager(cfg)
if err != nil {
    return fmt.Errorf("manager init: %w", err)
}

When it happens

Trigger: Calling NewManager(nil), or passing a *ManagerConfig variable that was never initialized (zero-value declared but not allocated).

Common situations: Refactoring that removed config construction, config-loading failure silently returning nil, or tests like TestNewManager_NilConfig exercising the guard.

Related errors

• unsupported format: %s
• result cannot be nil
• result cannot be nil
• output manager is closed
• failed to create TXT file: %w

AI-assisted analysis of shadow1ng/fscan@95cc12e753 (2026-09-06). Data as JSON: /api/errors/6ec4f3abd1daa458. Report an issue: GitHub.