Yesterday I made an "emergency" update to the TFS build library on DynamicsAX Admin on CodePlex. A while ago we implemented ASYNC activities as well as support for the AXBUILD process at about the same time. Some copy/paste errors resulted in the regular compile (non-axbuild) to no longer read the compiler log - so no errors or warnings were being shown. We hadn't actually ran into this ourselves, since we're most occupied on R2 and we always use the latest kernel for builds, so we were able to use AXBUILD for all R2 clients. And, admittedly, our old clients were still running on older versions of the build libraries - so we didn't see the error until now.
With that being said, I strongly encourage you to get the new library, since you won't actually see any compiler output probably unless you're using AXBUILD.
And while we're at it, I felt it good enough to release a beta version of the AX2009 port of the library as well. There were tons of fixes over the past week, in case anyone used the source code to build their own. There are a few caveats. We ran into issues with the DB restore activity on SQL 2008 R2, since one feature we were using in the SQL scripts wouldn't work. As a result we changed to using the SMO libraries (SQL Management Objects). Right now we're making the assumption that 1) the SMO libraries are installed and 2) that they are for SQL 2008 R2. Unfortunately I haven't had time to make any sort of documentation and there are several new activities, mostly around the Application Files (in lieue of model store activities). Feel free to contact me with questions. Currently I have only built the libraries against TFS 2013 assemblies, please drop me a line or leave a comment if you have a need for a TFS 2012 version.
Since 2009 layers don't have version number, we include an option in our CombineXPOs step that creates a Macro with a name of your choosing and contents of your choosing. You can set the build number as the contents of the macro, and perhaps include a mod to your about screen to show whatever is in the macro (which will be created on the fly).