debrelease: 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/debrelease - from package: devscripts

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

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