link-unresolved-function: 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/link-unresolved-function - from package: piglit

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

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