scissor-stencil-clear: 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/scissor-stencil-clear - from package: piglit

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

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