gnunet-setup: 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/gnunet-setup - from package: gnunet-gtk

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

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