flake: 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/flake - from package: flake

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

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