lurker-index: 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/lurker-index - from package: lurker

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

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