cupt: command not found

Have You tried accessing the binary with the full path?

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/lib/debug/usr/bin/cupt - from package: cupt-dbg
/usr/bin/cupt - from package: cupt

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