gauche-package: 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/gauche-package - from package: gauche-dev

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

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