compiling problem

Hi all,

I am cleaning my working tree to get LibreOffice compile and create clean commits, but now I have 
this error:

[CXX] pyuno/source/module/pyuno.cxx
In file included from /home/aollier/libreoffice-dev/pyuno/source/module/pyuno_runtime.cxx:23:
/home/aollier/libreoffice-dev/pyuno/source/module/pyuno_impl.hxx:27:10: fatal error: Python.h: 
Aucun fichier ou dossier de ce type
 #include <Python.h>
                  ^~~~~~~~~~
compilation terminated.
make[1]: *** [/home/aollier/libreoffice-dev/solenv/gbuild/LinkTarget.mk:292: 
/home/aollier/libreoffice-dev/workdir/CxxObject/pyuno/source/module/pyuno_runtime.o] Error 1
make[1]: *** Attente des tâches non terminées....
make: *** [Makefile:282: build] Error 2

But I didn't delete any Python.h file and git status confirms that. I didn't change pyuno_runtime 
neither.
Furthermore re-running sudo apt-get build-dep libreoffice does nothing:
$ sudo apt-get build-dep libreoffice
Lecture des listes de paquets... Fait
Lecture des listes de paquets... Fait
Construction de l'arbre des dépendances
Lecture des informations d'état... Fait
0 mis à jour, 0 nouvellement installés, 0 à enlever et 0 non mis à jour.

Anyone have an idea of what the problem is?

Adrien Ollier