cat5rancid: command not found

Have You tried accessing the binary with the full path?

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/cat5rancid - from package: rancid

You may install the required package with command apt-get install {package}
Error in other languages:
cat5rancid: bevel nie gevind nie
cat5rancid: comandă negăsită
cat5rancid: comando não encontrado
cat5rancid: commande introuvable
cat5rancid: command not found
cat5rancid: käsku ei ole
cat5rancid: không tìm thấy lệnh
cat5rancid: komanda nerasta
cat5rancid: Kommando nicht gefunden.
cat5rancid: kommandot finns inte
cat5rancid: komut yok
cat5rancid: nie znaleziono polecenia
cat5rancid: níor aimsíodh an t-ordú
cat5rancid: no se encontró la orden
cat5rancid: no s'ha trobat l'ordre
cat5rancid: opdracht niet gevonden
cat5rancid: parancs nem található
cat5rancid: perintah tidak ditemukan
cat5rancid: príkaz nenájdený
cat5rancid: příkaz nenalezen
cat5rancid: команда не найдена
cat5rancid: командата не е открита
cat5rancid: 命令找不到
cat5rancid: コマンドが見つかりません