ragel: 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/ragel - from package: ragel

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