gosh: 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/gosh - from package: gauche

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

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