Two things are negatively impacting GHC CI right now:
Darwin runner capacity is down to one machine, since the other three are paused. The problem and solution are known[1], but until the fix is implemented in GHC, expect pipelines to get backed up. I will work on a patch this morning
The other problem is one I just noticed, and I don't have any good info about it yet. The symptom is that Marge batch merges are failing reliably. Three patches that do fine individually somehow cause a type error in the hadrian-ghc-in-ghci job when combined[2]. The only clue is the error itself, which complains of an out-of-scope data constructor "ArchJavaScript" in the file compiler/GHC/Driver/Main.hs. A cursory look at the individual patches doesn't shed any light. I just rebased all of them to see if I can shake the error out of them that way. Any knowledge that can be brought to bear would be appreciated
-Bryan