depthrange-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/depthrange-clear - from package: piglit

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

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