cusp: 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/bin/cusp - from package: emboss

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