glx-query-renderer-coverage: 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/glx-query-renderer-coverage - from package: piglit

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

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