git-release: 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 Debian possible default full paths are:

/usr/bin/git-release - from package: git-extras

You may install the required package with command apt-get install {package}

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