arb_explicit_uniform_location-inactive-uniform: 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_explicit_uniform_location-inactive-uniform - from package: piglit

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

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