fedmsg-relay: 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/fedmsg-relay - from package: fedmsg-relay

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

On Debian possible default full paths are:

/usr/bin/fedmsg-relay - from package: fedmsg-relay

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

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