piglit-merge-results: 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/bin/piglit-merge-results - from package: piglit

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

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