makepasswd: 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

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/makepasswd - from package: makepasswd

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