cpanm: 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/cpanm - from package: cpanminus

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

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