kconfig_compiler4: 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/kconfig_compiler4 - from package: kdelibs-devel

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

Error in other languages:
kconfig_compiler4: bevel nie gevind nie
kconfig_compiler4: comandă negăsită
kconfig_compiler4: comando não encontrado
kconfig_compiler4: commande introuvable
kconfig_compiler4: command not found
kconfig_compiler4: käsku ei ole
kconfig_compiler4: không tìm thấy lệnh
kconfig_compiler4: komanda nerasta
kconfig_compiler4: Kommando nicht gefunden.
kconfig_compiler4: kommandot finns inte
kconfig_compiler4: komut yok
kconfig_compiler4: nie znaleziono polecenia
kconfig_compiler4: níor aimsíodh an t-ordú
kconfig_compiler4: no se encontró la orden
kconfig_compiler4: no s'ha trobat l'ordre
kconfig_compiler4: opdracht niet gevonden
kconfig_compiler4: parancs nem található
kconfig_compiler4: perintah tidak ditemukan
kconfig_compiler4: príkaz nenájdený
kconfig_compiler4: příkaz nenalezen
kconfig_compiler4: команда не найдена
kconfig_compiler4: командата не е открита
kconfig_compiler4: 命令找不到
kconfig_compiler4: コマンドが見つかりません