moin: command not found

Have You tried accessing the binary with the full path?

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/moin - from package: python-moinmoin

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