lunch: 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/lunch - from package: python-lunch

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

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