multidelta: 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 Debian possible default full paths are:

/usr/bin/multidelta - from package: delta

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