crossbar: 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/crossbar - from package: piglit

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

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