git-sh: 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-sh - from package: git-sh

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

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