clearbuffer-display-lists: 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/clearbuffer-display-lists - from package: piglit

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

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