haserl: 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/haserl - from package: haserl

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

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