dh_sphinxdoc: 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/dh_sphinxdoc - from package: sphinx-common

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

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