piglit_test: 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 Debian possible default full paths are:

/usr/lib/plainbox-providers-1/checkbox/bin/piglit_test - from package: plainbox-provider-checkbox

You may install the required package with command apt-get install {package}

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