xeno: 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/xeno - from package: xenomai-runtime

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

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