cpan-upload: 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/cpan-upload - from package: libcpan-uploader-perl

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