qemubuilder: 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/sbin/qemubuilder - from package: qemubuilder

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

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