waf-2.6: 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/bin/waf-2.6 - from package: waf

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

Error in other languages:
waf-2.6: bevel nie gevind nie
waf-2.6: comandă negăsită
waf-2.6: comando não encontrado
waf-2.6: commande introuvable
waf-2.6: command not found
waf-2.6: käsku ei ole
waf-2.6: không tìm thấy lệnh
waf-2.6: komanda nerasta
waf-2.6: Kommando nicht gefunden.
waf-2.6: kommandot finns inte
waf-2.6: komut yok
waf-2.6: nie znaleziono polecenia
waf-2.6: níor aimsíodh an t-ordú
waf-2.6: no se encontró la orden
waf-2.6: no s'ha trobat l'ordre
waf-2.6: opdracht niet gevonden
waf-2.6: parancs nem található
waf-2.6: perintah tidak ditemukan
waf-2.6: príkaz nenájdený
waf-2.6: příkaz nenalezen
waf-2.6: команда не найдена
waf-2.6: командата не е открита
waf-2.6: 命令找不到
waf-2.6: コマンドが見つかりません