quad-invariance: 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/lib64/piglit/bin/quad-invariance - from package: piglit

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

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