sync_api: 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/sync_api - from package: piglit

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

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