millstone: 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/millstone - from package: node-millstone
/usr/lib/nodejs/millstone/bin/millstone - from package: node-millstone

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

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