rst2pdf: 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 CentOS possible default full paths are:

/usr/bin/rst2pdf - from package: rst2pdf

You may install the required package with command yum install {package}

On Debian possible default full paths are:

/usr/bin/rst2pdf - from package: rst2pdf

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

Error in other languages:
rst2pdf: bevel nie gevind nie
rst2pdf: comandă negăsită
rst2pdf: comando não encontrado
rst2pdf: commande introuvable
rst2pdf: command not found
rst2pdf: käsku ei ole
rst2pdf: không tìm thấy lệnh
rst2pdf: komanda nerasta
rst2pdf: Kommando nicht gefunden.
rst2pdf: kommandot finns inte
rst2pdf: komut yok
rst2pdf: nie znaleziono polecenia
rst2pdf: níor aimsíodh an t-ordú
rst2pdf: no se encontró la orden
rst2pdf: no s'ha trobat l'ordre
rst2pdf: opdracht niet gevonden
rst2pdf: parancs nem található
rst2pdf: perintah tidak ditemukan
rst2pdf: príkaz nenájdený
rst2pdf: příkaz nenalezen
rst2pdf: команда не найдена
rst2pdf: командата не е открита
rst2pdf: 命令找不到
rst2pdf: コマンドが見つかりません