lunit: 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/lunit - from package: lua-lunit

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

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