textureGather: 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/textureGather - from package: piglit

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

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