qbrew: 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/qbrew - from package: qbrew

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

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