Our friendly continuous integration system, Hudson, mirrors the mono, mcs, and gtk-sharp trees every hour looking for new code to build. However, if a commit is made to one of these projects that is required by code about to be committed to uia2atk, and Hudson hasn't had a chance to mirror the latest changes, the build will break. To avoid this situation, you can ask Hudson to rebuild individual modules on demand.
If a rebuild is required in mono or mcs:
!hudson build mono-core_trunk_tarball
If a rebuild is required in gtk-sharp:
!hudson build gtk-sharp212_branch_tarball
The latest targets for the build command are available on Hudson's web interface.