setlock: command not found

Have You tried accessing the binary with the full path?

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/setlock - from package: daemontools

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