rosdep-source: 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/rosdep-source - from package: python-rosdep

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

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