guilt-repair: command not found

Have You tried accessing the binary with the full path?

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/guilt-repair - from package: guilt

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