arb_framebuffer_srgb-srgb_conformance: 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/arb_framebuffer_srgb-srgb_conformance - from package: piglit

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

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