rebuildd-httpd: 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/sbin/rebuildd-httpd - from package: rebuildd

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