gnatchop: 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 CentOS possible default full paths are:

/usr/bin/gnatchop - from package: gcc-gnat

You may install the required package with command yum install {package}

On Debian possible default full paths are:

/usr/bin/gnatchop - from package: gnat-4.9

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

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