debmany: 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/debmany - from package: debian-goodies

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