polari: 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/bin/polari - from package: polari

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