apache/answer · error

failed to run go list: %w

Error message

failed to run go list: %w

What it means

copyUIFiles runs `go list -mod=mod -m -f {{.Dir}} github.com/apache/answer` to locate the module directory containing the prebuilt UI files; if that command fails it returns 'failed to run go list: <err>'.

Source

Thrown at internal/cli/build.go:327

		pluginName := filepath.Base(p.Name)
		if !strings.HasPrefix(p.Name, "github.com/apache/answer-plugins/") {
			fmt.Printf("try to copy dir from %s to %s\n", pluginDir, filepath.Join(pluginsDir, pluginName))
			err = copyDirEntries(os.DirFS(pluginDir), ".", filepath.Join(pluginsDir, pluginName), "node_modules")
			if err != nil {
				return err
			}
		}
	}
	return nil
}

// copyUIFiles copy ui files from answer module to tmp dir
func copyUIFiles(b *buildingMaterial) (err error) {
	goListCmd := b.newExecCmd("go", "list", "-mod=mod", "-m", "-f", "{{.Dir}}", "github.com/apache/answer")
	buf := new(bytes.Buffer)
	goListCmd.Stdout = buf
	if err = goListCmd.Run(); err != nil {
		return fmt.Errorf("failed to run go list: %w", err)
	}

	answerDir := strings.TrimSpace(buf.String())
	goModUIDir := filepath.Join(answerDir, "ui")
	localUIBuildDir := filepath.Join(b.tmpDir, "vendor/github.com/apache/answer/ui/")
	// The node_modules folder generated during development will interfere packaging, so it needs to be ignored.
	if err = copyDirEntries(os.DirFS(goModUIDir), ".", localUIBuildDir, "node_modules"); err != nil {
		return fmt.Errorf("failed to copy ui files: %w", err)
	}

	pluginsDir := filepath.Join(b.tmpDir, "vendor/github.com/apache/answer-plugins/")
	localUIPluginDir := filepath.Join(localUIBuildDir, "src/plugins/")

	// copy plugins dir
	fmt.Printf("try to copy dir from %s to %s\n", pluginsDir, localUIPluginDir)

	// if plugins dir not exist means no plugins
	if !dir.CheckDirExist(pluginsDir) {

View on GitHub (pinned to 3b9f137061)

Solutions

1. Run the build from a directory whose go.mod requires github.com/apache/answer (or set ANSWER_MODULE to a local checkout).
2. Ensure `go` is installed and on PATH in the build environment.
3. Run `go mod download github.com/apache/answer` (with correct GOPROXY) then retry the build.
4. Check go.mod/go.sum consistency (`go mod tidy`) and avoid -mod=vendor conflicts with -mod=mod usage.

Example fix

// before
$ cd ./some-random-dir && answer build
// after
$ cd /path/to/project-with-answer-in-go.mod
$ go mod download github.com/apache/answer
$ answer build

go version || { echo 'go toolchain required'; exit 1; }
go list -mod=mod -m -f '{{.Dir}}' github.com/apache/answer || { echo 'answer module not in go.mod; set ANSWER_MODULE'; exit 1; }

if err := copyUIFiles(b); err != nil {
  if strings.HasPrefix(err.Error(), "failed to run go list:") {
    if dir := os.Getenv("ANSWER_MODULE"); dir != "" {
      return copyUIFromLocal(dir)
    }
  }
  return err
}

When it happens

Trigger: `answer build` executed outside a Go module that depends on github.com/apache/answer, go missing from PATH, corrupted module cache, go.mod/go.sum out of sync, or the module not yet downloaded and download failing (offline).

Common situations: Running the build CLI in a directory without go.mod, CI images without the Go toolchain, vendoring inconsistencies (GOFLAGS=-mod=vendor conflicts), Go proxy unreachable (GOPROXY blocked).

Related errors

• failed to clone %s@%s: %w Tip: set ANSWER_MODULE to a local
• failed to install plugin dependencies: %w
• failed to open source file %s: %w
• failed to create destination file %s: %w
• validate check exception

AI-assisted analysis of apache/answer@3b9f137061 (2026-09-05). Data as JSON: /api/errors/24d72c0b1e638e4f. Report an issue: GitHub.