gost-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/gost-hash - from package: rhash

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

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