powerline-config: 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/powerline-config - from package: powerline

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