useshaderprogram-flushverts-1: 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/useshaderprogram-flushverts-1 - from package: piglit

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

Error in other languages:
useshaderprogram-flushverts-1: bevel nie gevind nie
useshaderprogram-flushverts-1: comandă negăsită
useshaderprogram-flushverts-1: comando não encontrado
useshaderprogram-flushverts-1: commande introuvable
useshaderprogram-flushverts-1: command not found
useshaderprogram-flushverts-1: käsku ei ole
useshaderprogram-flushverts-1: không tìm thấy lệnh
useshaderprogram-flushverts-1: komanda nerasta
useshaderprogram-flushverts-1: Kommando nicht gefunden.
useshaderprogram-flushverts-1: kommandot finns inte
useshaderprogram-flushverts-1: komut yok
useshaderprogram-flushverts-1: nie znaleziono polecenia
useshaderprogram-flushverts-1: níor aimsíodh an t-ordú
useshaderprogram-flushverts-1: no se encontró la orden
useshaderprogram-flushverts-1: no s'ha trobat l'ordre
useshaderprogram-flushverts-1: opdracht niet gevonden
useshaderprogram-flushverts-1: parancs nem található
useshaderprogram-flushverts-1: perintah tidak ditemukan
useshaderprogram-flushverts-1: príkaz nenájdený
useshaderprogram-flushverts-1: příkaz nenalezen
useshaderprogram-flushverts-1: команда не найдена
useshaderprogram-flushverts-1: командата не е открита
useshaderprogram-flushverts-1: 命令找不到
useshaderprogram-flushverts-1: コマンドが見つかりません