AdguardTeam/AdGuardHome · error

parsing uid: %w

Error message

parsing uid: %w

What it means

After a successful user lookup, the Uid string failed strconv.Atoi — the user database returned a non-numeric uid. UIDs are numeric by definition, so this signals malformed system data rather than bad input.

Source

Thrown at internal/aghos/user_unix.go:39

	}

	err = syscall.Setgid(gid)
	if err != nil {
		return fmt.Errorf("setting gid: %w", err)
	}

	return nil
}

func setUser(userName string) (err error) {
	u, err := user.Lookup(userName)
	if err != nil {
		return fmt.Errorf("looking up user: %w", err)
	}

	uid, err := strconv.Atoi(u.Uid)
	if err != nil {
		return fmt.Errorf("parsing uid: %w", err)
	}

	err = syscall.Setuid(uid)
	if err != nil {
		return fmt.Errorf("setting uid: %w", err)
	}

	return nil
}

View on GitHub (pinned to b41aefbe51)

Solutions

1. Inspect the entry: getent passwd <name> — third field must be an integer
2. Repair /etc/passwd or the LDAP uidNumber attribute
3. Defensively, prefer strconv.ParseUint and validate the range before Setuid

u, err := user.Lookup(name)
if err == nil {
    if _, err := strconv.Atoi(u.Uid); err != nil { /* malformed passwd DB */ }
}

When it happens

Trigger: user.Lookup returns a User with a non-numeric Uid field — corrupted /etc/passwd, a broken NSS module, or an auth backend returning empty/malformed uid fields.

Common situations: Hand-edited /etc/passwd with errors; LDAP entries with invalid uidNumber attributes; essentially never occurs with a healthy user database.

Related errors

• parsing gid: %w
• looking up group: %w
• looking up user: %w
• setting gid: %w
• setting uid: %w

AI-assisted analysis of AdguardTeam/AdGuardHome@b41aefbe51 (2026-08-27). Data as JSON: /api/errors/0b43d8e1bdc32403. Report an issue: GitHub.