rivrancid: 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/lib/rancid/bin/rivrancid - from package: rancid

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

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