echo_supervisord_conf: 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/echo_supervisord_conf - from package: supervisor

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

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