Auf ubuntu 14.04:
sudo apt-file search ffi.h
ergab:
chipmunk-dev: /usr/include/chipmunk/chipmunk_ffi.h
ghc-doc: /usr/share/doc/ghc-doc/html/users_guide/ffi.html
jython-doc: /usr/share/doc/jython-doc/html/javadoc/org/python/modules/jffi/jffi.html
libffi-dev: /usr/include/x86_64-linux-gnu/ffi.h
libffi-dev: /usr/share/doc/libffi6/html/Using-libffi.html
libgirepository1.0-dev: /usr/include/gobject-introspection-1.0/girffi.h
libgirepository1.0-doc: /usr/share/gtk-doc/html/gi/gi-girffi.html
mlton-basis: /usr/lib/mlton/include/basis-ffi.h
pypy-doc: /usr/share/doc/pypy-doc/html/config/objspace.usemodules._ffi.html
pypy-doc: /usr/share/doc/pypy-doc/html/config/objspace.usemodules._rawffi.html
pypy-doc: /usr/share/doc/pypy-doc/html/rffi.html
Ich habe mich entschieden, libffi-dev zu installieren
sudo apt-get install libffi-dev
hat perfekt funktioniert