fdo23670-depth_test: 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/fdo23670-depth_test - from package: piglit

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

Error in other languages:
fdo23670-depth_test: bevel nie gevind nie
fdo23670-depth_test: comandă negăsită
fdo23670-depth_test: comando não encontrado
fdo23670-depth_test: commande introuvable
fdo23670-depth_test: command not found
fdo23670-depth_test: käsku ei ole
fdo23670-depth_test: không tìm thấy lệnh
fdo23670-depth_test: komanda nerasta
fdo23670-depth_test: Kommando nicht gefunden.
fdo23670-depth_test: kommandot finns inte
fdo23670-depth_test: komut yok
fdo23670-depth_test: nie znaleziono polecenia
fdo23670-depth_test: níor aimsíodh an t-ordú
fdo23670-depth_test: no se encontró la orden
fdo23670-depth_test: no s'ha trobat l'ordre
fdo23670-depth_test: opdracht niet gevonden
fdo23670-depth_test: parancs nem található
fdo23670-depth_test: perintah tidak ditemukan
fdo23670-depth_test: príkaz nenájdený
fdo23670-depth_test: příkaz nenalezen
fdo23670-depth_test: команда не найдена
fdo23670-depth_test: командата не е открита
fdo23670-depth_test: 命令找不到
fdo23670-depth_test: コマンドが見つかりません