debsums: 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/debsums - from package: debsums

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

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