glx-get-current-display-ext: 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/glx-get-current-display-ext - from package: piglit

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

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