line-flat-clip-color: 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/line-flat-clip-color - from package: piglit

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

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