rancid_par: 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/rancid_par - from package: rancid

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