pygobject-codegen-2.0: 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 CentOS possible default full paths are:

/usr/bin/pygobject-codegen-2.0 - from package: pygobject2-codegen

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

On Debian possible default full paths are:

/usr/bin/pygobject-codegen-2.0 - from package: python-gobject-2-dev

You may install the required package with command apt-get install {package}
Error in other languages:
pygobject-codegen-2.0: bevel nie gevind nie
pygobject-codegen-2.0: comandă negăsită
pygobject-codegen-2.0: comando não encontrado
pygobject-codegen-2.0: commande introuvable
pygobject-codegen-2.0: command not found
pygobject-codegen-2.0: käsku ei ole
pygobject-codegen-2.0: không tìm thấy lệnh
pygobject-codegen-2.0: komanda nerasta
pygobject-codegen-2.0: Kommando nicht gefunden.
pygobject-codegen-2.0: kommandot finns inte
pygobject-codegen-2.0: komut yok
pygobject-codegen-2.0: nie znaleziono polecenia
pygobject-codegen-2.0: níor aimsíodh an t-ordú
pygobject-codegen-2.0: no se encontró la orden
pygobject-codegen-2.0: no s'ha trobat l'ordre
pygobject-codegen-2.0: opdracht niet gevonden
pygobject-codegen-2.0: parancs nem található
pygobject-codegen-2.0: perintah tidak ditemukan
pygobject-codegen-2.0: príkaz nenájdený
pygobject-codegen-2.0: příkaz nenalezen
pygobject-codegen-2.0: команда не найдена
pygobject-codegen-2.0: командата не е открита
pygobject-codegen-2.0: 命令找不到
pygobject-codegen-2.0: コマンドが見つかりません