whups-git-hook: 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/whups-git-hook - from package: php-horde-whups

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

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