gen_delete_while_active: 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/gen_delete_while_active - from package: piglit

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

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