Today the start of "operation libtool-slay" will be made in testing. Operation libtool-slay means we get rid of most .la files in packages. Libtool archive files are pure evil on a system managed by a package manager. They pollute the linking process of other libraries and make version upgrades of single binaries a big hell. This has been observed with much small libraries with only a few dependencies, but it would hit bigger packages like gtk2 in the future. Since all major distributions are already removing these files whenever possible, now is the time to do it on archlinux too.
What this means to you as end-user is that any library you have compiled yourself and contains .la files, has references to non-existing .la files which were previously included in official archlinux packages. On runtime, you will not notify anything at all of this operation. At compile time however, expect build errors about missing .la files. The bug isn't in the package that misses the .la file then, but in the package that references this .la file.
During this operation many build errors will occur, that's why we do this operation in testing first. When we finish the operation, packages will be moved to current and extra and an announcement is made on the website.
After this operation, there is still a possibility though that we missed libraries, please report bugs about what .la file was missing, what package you where compiling and what dependencies it has (including a full tree from the application up to the library with the missing .la file).