luadoc: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On Debian possible default full paths are:

/usr/bin/luadoc - from package: luadoc

You may install the required package with command apt-get install {package}

Error in other languages:
luadoc: bevel nie gevind nie
luadoc: comandă negăsită
luadoc: comando não encontrado
luadoc: commande introuvable
luadoc: command not found
luadoc: käsku ei ole
luadoc: không tìm thấy lệnh
luadoc: komanda nerasta
luadoc: Kommando nicht gefunden.
luadoc: kommandot finns inte
luadoc: komut yok
luadoc: nie znaleziono polecenia
luadoc: níor aimsíodh an t-ordú
luadoc: no se encontró la orden
luadoc: no s'ha trobat l'ordre
luadoc: opdracht niet gevonden
luadoc: parancs nem található
luadoc: perintah tidak ditemukan
luadoc: príkaz nenájdený
luadoc: příkaz nenalezen
luadoc: команда не найдена
luadoc: командата не е открита
luadoc: 命令找不到
luadoc: コマンドが見つかりません