glx-multithread-makecurrent-2: 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-multithread-makecurrent-2 - from package: piglit

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

Error in other languages:
glx-multithread-makecurrent-2: bevel nie gevind nie
glx-multithread-makecurrent-2: comandă negăsită
glx-multithread-makecurrent-2: comando não encontrado
glx-multithread-makecurrent-2: commande introuvable
glx-multithread-makecurrent-2: command not found
glx-multithread-makecurrent-2: käsku ei ole
glx-multithread-makecurrent-2: không tìm thấy lệnh
glx-multithread-makecurrent-2: komanda nerasta
glx-multithread-makecurrent-2: Kommando nicht gefunden.
glx-multithread-makecurrent-2: kommandot finns inte
glx-multithread-makecurrent-2: komut yok
glx-multithread-makecurrent-2: nie znaleziono polecenia
glx-multithread-makecurrent-2: níor aimsíodh an t-ordú
glx-multithread-makecurrent-2: no se encontró la orden
glx-multithread-makecurrent-2: no s'ha trobat l'ordre
glx-multithread-makecurrent-2: opdracht niet gevonden
glx-multithread-makecurrent-2: parancs nem található
glx-multithread-makecurrent-2: perintah tidak ditemukan
glx-multithread-makecurrent-2: príkaz nenájdený
glx-multithread-makecurrent-2: příkaz nenalezen
glx-multithread-makecurrent-2: команда не найдена
glx-multithread-makecurrent-2: командата не е открита
glx-multithread-makecurrent-2: 命令找不到
glx-multithread-makecurrent-2: コマンドが見つかりません