Compiling SDL 1.2.14 - "

I’d like to compile SDL myself, and add changes later. After downloading the source of SDL 1.2.14, I didn’t find a file just named “makefile”. I’m using Windows and so I had to install MSYS, what I did next. GCC is already installed.
I followed some instructions and typed “./configure” (in msys), and after a while it finished, and I typed “make”. After some output like “/bin/sh ./libtool -mode=compile …”. At the end of the “command”, there is some error output:

libtool: compile: unable to infer tagged configuration
libtool: compile: specify a tag with `–tag?

What am I doing wrong?