x86_64-w64-mingw32-gnatmake-win32: 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/x86_64-w64-mingw32-gnatmake-win32 - from package: gnat-mingw-w64-x86-64

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

Error in other languages:
x86_64-w64-mingw32-gnatmake-win32: bevel nie gevind nie
x86_64-w64-mingw32-gnatmake-win32: comandă negăsită
x86_64-w64-mingw32-gnatmake-win32: comando não encontrado
x86_64-w64-mingw32-gnatmake-win32: commande introuvable
x86_64-w64-mingw32-gnatmake-win32: command not found
x86_64-w64-mingw32-gnatmake-win32: käsku ei ole
x86_64-w64-mingw32-gnatmake-win32: không tìm thấy lệnh
x86_64-w64-mingw32-gnatmake-win32: komanda nerasta
x86_64-w64-mingw32-gnatmake-win32: Kommando nicht gefunden.
x86_64-w64-mingw32-gnatmake-win32: kommandot finns inte
x86_64-w64-mingw32-gnatmake-win32: komut yok
x86_64-w64-mingw32-gnatmake-win32: nie znaleziono polecenia
x86_64-w64-mingw32-gnatmake-win32: níor aimsíodh an t-ordú
x86_64-w64-mingw32-gnatmake-win32: no se encontró la orden
x86_64-w64-mingw32-gnatmake-win32: no s'ha trobat l'ordre
x86_64-w64-mingw32-gnatmake-win32: opdracht niet gevonden
x86_64-w64-mingw32-gnatmake-win32: parancs nem található
x86_64-w64-mingw32-gnatmake-win32: perintah tidak ditemukan
x86_64-w64-mingw32-gnatmake-win32: príkaz nenájdený
x86_64-w64-mingw32-gnatmake-win32: příkaz nenalezen
x86_64-w64-mingw32-gnatmake-win32: команда не найдена
x86_64-w64-mingw32-gnatmake-win32: командата не е открита
x86_64-w64-mingw32-gnatmake-win32: 命令找不到
x86_64-w64-mingw32-gnatmake-win32: コマンドが見つかりません