control_rancid: 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/control_rancid - from package: rancid

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

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