mustang: 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/mustang - from package: mustang

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

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