useprogram-flushverts-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/useprogram-flushverts-2 - from package: piglit

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

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