ao-dbg: 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/ao-dbg - from package: altos

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

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