aws_completer: 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/aws_completer - from package: awscli

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

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