./config之后，出现如下问题：

checking for sdl-config... no

checking for SDL - version >= 1.2.0... no

*** The sdl-config script installed by SDL could not be found

*** If SDL was installed in PREFIX, make sure PREFIX/bin is in

*** your path, or set the SDL_CONFIG environment variable to the

*** full path to sdl-config.

configure: error: *** SDL version 1.2.0 not found!

这是因为没安装libsdl1.2，安装后即可：

sudo apt-get install build-essential libsdl1.2-dev