sumpix: 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/sumpix - from package: wcstools

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

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