refine_wavelength: 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/refine_wavelength - from package: pyfai

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

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