gl-2.0-edgeflag: 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/gl-2.0-edgeflag - from package: piglit

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

Error in other languages:
gl-2.0-edgeflag: bevel nie gevind nie
gl-2.0-edgeflag: comandă negăsită
gl-2.0-edgeflag: comando não encontrado
gl-2.0-edgeflag: commande introuvable
gl-2.0-edgeflag: command not found
gl-2.0-edgeflag: käsku ei ole
gl-2.0-edgeflag: không tìm thấy lệnh
gl-2.0-edgeflag: komanda nerasta
gl-2.0-edgeflag: Kommando nicht gefunden.
gl-2.0-edgeflag: kommandot finns inte
gl-2.0-edgeflag: komut yok
gl-2.0-edgeflag: nie znaleziono polecenia
gl-2.0-edgeflag: níor aimsíodh an t-ordú
gl-2.0-edgeflag: no se encontró la orden
gl-2.0-edgeflag: no s'ha trobat l'ordre
gl-2.0-edgeflag: opdracht niet gevonden
gl-2.0-edgeflag: parancs nem található
gl-2.0-edgeflag: perintah tidak ditemukan
gl-2.0-edgeflag: príkaz nenájdený
gl-2.0-edgeflag: příkaz nenalezen
gl-2.0-edgeflag: команда не найдена
gl-2.0-edgeflag: командата не е открита
gl-2.0-edgeflag: 命令找不到
gl-2.0-edgeflag: コマンドが見つかりません