gl-3.1-primitive-restart-xfb: 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/gl-3.1-primitive-restart-xfb - from package: piglit

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

Error in other languages:
gl-3.1-primitive-restart-xfb: bevel nie gevind nie
gl-3.1-primitive-restart-xfb: comandă negăsită
gl-3.1-primitive-restart-xfb: comando não encontrado
gl-3.1-primitive-restart-xfb: commande introuvable
gl-3.1-primitive-restart-xfb: command not found
gl-3.1-primitive-restart-xfb: käsku ei ole
gl-3.1-primitive-restart-xfb: không tìm thấy lệnh
gl-3.1-primitive-restart-xfb: komanda nerasta
gl-3.1-primitive-restart-xfb: Kommando nicht gefunden.
gl-3.1-primitive-restart-xfb: kommandot finns inte
gl-3.1-primitive-restart-xfb: komut yok
gl-3.1-primitive-restart-xfb: nie znaleziono polecenia
gl-3.1-primitive-restart-xfb: níor aimsíodh an t-ordú
gl-3.1-primitive-restart-xfb: no se encontró la orden
gl-3.1-primitive-restart-xfb: no s'ha trobat l'ordre
gl-3.1-primitive-restart-xfb: opdracht niet gevonden
gl-3.1-primitive-restart-xfb: parancs nem található
gl-3.1-primitive-restart-xfb: perintah tidak ditemukan
gl-3.1-primitive-restart-xfb: príkaz nenájdený
gl-3.1-primitive-restart-xfb: příkaz nenalezen
gl-3.1-primitive-restart-xfb: команда не найдена
gl-3.1-primitive-restart-xfb: командата не е открита
gl-3.1-primitive-restart-xfb: 命令找不到
gl-3.1-primitive-restart-xfb: コマンドが見つかりません