parrot_debugger: 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/parrot_debugger - from package: parrot-devel

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