glsl-1.50-gs-output-layout-qualifiers: 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/glsl-1.50-gs-output-layout-qualifiers - from package: piglit

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

Error in other languages:
glsl-1.50-gs-output-layout-qualifiers: bevel nie gevind nie
glsl-1.50-gs-output-layout-qualifiers: comandă negăsită
glsl-1.50-gs-output-layout-qualifiers: comando não encontrado
glsl-1.50-gs-output-layout-qualifiers: commande introuvable
glsl-1.50-gs-output-layout-qualifiers: command not found
glsl-1.50-gs-output-layout-qualifiers: käsku ei ole
glsl-1.50-gs-output-layout-qualifiers: không tìm thấy lệnh
glsl-1.50-gs-output-layout-qualifiers: komanda nerasta
glsl-1.50-gs-output-layout-qualifiers: Kommando nicht gefunden.
glsl-1.50-gs-output-layout-qualifiers: kommandot finns inte
glsl-1.50-gs-output-layout-qualifiers: komut yok
glsl-1.50-gs-output-layout-qualifiers: nie znaleziono polecenia
glsl-1.50-gs-output-layout-qualifiers: níor aimsíodh an t-ordú
glsl-1.50-gs-output-layout-qualifiers: no se encontró la orden
glsl-1.50-gs-output-layout-qualifiers: no s'ha trobat l'ordre
glsl-1.50-gs-output-layout-qualifiers: opdracht niet gevonden
glsl-1.50-gs-output-layout-qualifiers: parancs nem található
glsl-1.50-gs-output-layout-qualifiers: perintah tidak ditemukan
glsl-1.50-gs-output-layout-qualifiers: príkaz nenájdený
glsl-1.50-gs-output-layout-qualifiers: příkaz nenalezen
glsl-1.50-gs-output-layout-qualifiers: команда не найдена
glsl-1.50-gs-output-layout-qualifiers: командата не е открита
glsl-1.50-gs-output-layout-qualifiers: 命令找不到
glsl-1.50-gs-output-layout-qualifiers: コマンドが見つかりません