pyro-esd: 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 Debian possible default full paths are:

/usr/bin/pyro-esd - from package: pyro

You may install the required package with command apt-get install {package}

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