mapnik-render: 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/mapnik-render - from package: node-mapnik

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