Help with debugging a batch mode (or type checker) bug

Hi, In !1304 I'm currently having a bug where I get correct IdInfos for imported Ids in one-shot mode (-c), but not when I use batch mode (--make). If I add a few prints I can see that in hscIncrementalCompile right before hscIncrementalFrontend the hsc_HPT has the correct IdInfos for the imported Ids, but somehow in the desugarer output the IdInfo is lost. Can anyone point me to the right places in the typechecker or the desugarer for me to look at? Thanks, Ömer