Zipper: 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/Zipper - from package: zipper.app

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

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