rst2man: 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/rst2man - from package: python-docutils

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

Error in other languages:
rst2man: bevel nie gevind nie
rst2man: comandă negăsită
rst2man: comando não encontrado
rst2man: commande introuvable
rst2man: command not found
rst2man: käsku ei ole
rst2man: không tìm thấy lệnh
rst2man: komanda nerasta
rst2man: Kommando nicht gefunden.
rst2man: kommandot finns inte
rst2man: komut yok
rst2man: nie znaleziono polecenia
rst2man: níor aimsíodh an t-ordú
rst2man: no se encontró la orden
rst2man: no s'ha trobat l'ordre
rst2man: opdracht niet gevonden
rst2man: parancs nem található
rst2man: perintah tidak ditemukan
rst2man: príkaz nenájdený
rst2man: příkaz nenalezen
rst2man: команда не найдена
rst2man: командата не е открита
rst2man: 命令找不到
rst2man: コマンドが見つかりません