line-aa-width: 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-aa-width - from package: piglit

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

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