One of the changes[1] in transformers 0.4 is as follows: 0.3: newtype Identity a = Identity { runIdentity :: a } 0.4: newtype Identity a = Identity a runIdentity (Identity x) = x While this may seem benign, I've already seen three cases where this caused breakage[2][3][4]. Is there a reason for this change in 0.4? If not, I'd like to request moving back to the previous formulation to avoid unnecessary breakage. Michael [1] http://hdiff.luite.com/cgit/transformers/commit/Data/Functor/Identity.hs?id=cabf26451206cf1e223970b2df846132300c04d9&ss=1 [2] https://github.com/fpco/streaming-commons/pull/5 [3] https://github.com/ekmett/exceptions/pull/29 [4] https://github.com/ekmett/mtl/commit/d1a6253886a99215d5ff6afe3632b27e696d40b...