gnattest: 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/gnattest - from package: asis-programs

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

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