dul-upload-pack: 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/dul-upload-pack - from package: python-dulwich

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

On Debian possible default full paths are:

/usr/bin/dul-upload-pack - from package: python-dulwich

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