Hi,
For the tl;dr ones: re-run ./autogen.sh if you (since you'll) face a build problem after updating to last revision.
For the more interested ones:
I rewrote a bit (hum, more than a bit maybe :D) our Autotools build system for it to be more readable and maintainable.
What I did is to first remove use of deprecated stuff, and then split up into macros that are spread into different .m4, making each module confined in its file, and reducing main configure.ac's size. The code is sensibly the same as before, and the features should be identical; and hopefully the whole stuff will be easier to maintain and tune.
The new version should still work with fairly old setups (it's supposed to only depend on 2006-10-22 autoconf), and anyway it's only to generate the configure script.
However, if you find any problem with the updated (or not, BTW) Autotools setup, please report it :)
Now the problem: I moved many stuff to the m4 subdirectory, and autoconf/automake don't seem to be smart enough to find it has to include this "new" directory when it regenerate the files automatically upon `make' from the previous setup. Thus, you'll most probably need to re-run autogen.sh after updating to last revision, since the script includes the necessary clues needed for the first shot to work (later there won't be any problem since it'd already know it has to include m4 dir).
Sorry for the inconvenience.
Regards, Colomban