rdebsums: 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/rdebsums - from package: debsums

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

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