git-obliterate: 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-obliterate - from package: git-extras

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

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