cancel: 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/cancel - from package: cups-client
/usr/bin/cancel - from package: lprng

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

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