sbuild-checkpackages: 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/sbuild-checkpackages - from package: sbuild

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

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