nv_conditional_render-copypixels: 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/nv_conditional_render-copypixels - from package: piglit

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

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