glsl-fs-shader-stencil-export: 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-fs-shader-stencil-export - from package: piglit

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

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