arb_sampler_objects-sampler-incomplete: 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_sampler_objects-sampler-incomplete - from package: piglit

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

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