achilles: 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/achilles - from package: achilles

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

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