nettle-hash: 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/nettle-hash - from package: nettle-bin

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

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