dh_bash-completion: 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/dh_bash-completion - from package: bash-completion

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

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