catkin_generate_changelog: 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/catkin_generate_changelog - from package: python-catkin_pkg

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

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