mkdep: 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/mkdep - from package: bmake

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

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