debpkg: 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/debpkg - from package: devscripts

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

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