Grumpy harbormaster

I submitted two unrelated differentials today, D152 and D150. Somehow the Harbormaster builds of both have failed in the same peculiar way, silently dying apparently after right after finishing the initial ghc-cabal build. It's entirely possible I'm missing something silly here, but neither of the patches touch anything near Cabal or the build system so I'm a bit perplexed. What to do from here? Cheers, - Ben