poet: 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/poet - from package: libpoet-perl

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