golang/go · error

import path contains space character: %q

Error message

import path contains space character: %q

What it means

Returned by checkImportPath when allowSpace is false and a rune in the path is unicode whitespace (unicode.IsSpace). Most internal callers disable spaces; spaces in import paths break the build because they are ambiguous in go.mod, source files, and shell quoting.

Source

Thrown at src/cmd/compile/internal/noder/import.go:326

		return errors.New("import path contains NUL")
	}

	for ri := range base.ReservedImports {
		if path == ri {
			return fmt.Errorf("import path %q is reserved and cannot be used", path)
		}
	}

	for _, r := range path {
		switch {
		case r == utf8.RuneError:
			return fmt.Errorf("import path contains invalid UTF-8 sequence: %q", path)
		case r < 0x20 || r == 0x7f:
			return fmt.Errorf("import path contains control character: %q", path)
		case r == '\\':
			return fmt.Errorf("import path contains backslash; use slash: %q", path)
		case !allowSpace && unicode.IsSpace(r):
			return fmt.Errorf("import path contains space character: %q", path)
		case strings.ContainsRune("!\"#$%&'()*,:;<=>?[]^`{|}", r):
			return fmt.Errorf("import path contains invalid character '%c': %q", r, path)
		}
	}

	return nil
}

View on GitHub (pinned to b6b368adc5)

Solutions

1. Remove all whitespace characters from the import path.
2. Rename directories/files that contain spaces before referencing them as import paths.
3. If you genuinely need a path-with-spaces module, restructure to avoid it; Go import paths should be space-free.

Example fix

// before
 import "example.com/my project"
// after
 import "example.com/myproject"

for _, r := range path {
    if unicode.IsSpace(r) {
        return fmt.Errorf("whitespace in import path: %q", path)
    }
}

When it happens

Trigger: An import path contains a space, tab, or other unicode space (U+00A0, em-space, etc.) and the caller passed allowSpace=false (the default for source-level checks).

Common situations: Pasting a path from a formatted document that introduced non-breaking spaces; a directory name with spaces being used as an import path; tabs inside an import literal.

Related errors

• import path %q is reserved and cannot be used
• import path contains invalid UTF-8 sequence: %q
• import path contains control character: %q
• import path contains backslash; use slash: %q
• import path contains invalid character '%c': %q

AI-assisted analysis of golang/go@b6b368adc5 (2026-08-12). Data as JSON: /api/errors/6a3a311cd25f735c. Report an issue: GitHub.