will_stackoverflow: 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/will_stackoverflow - from package: will-crash

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

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