rubyforge: 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/rubyforge - from package: ruby-rubyforge

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

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