This shows up in more recent builds of my packages on Travis CI, e.g.
https://travis-ci.org/haskell-opengl/OpenGL/jobs/93814917#L296, but I don't have a clue what's causing it (GHC? cabal? Something else?), if I should ignore it or if I should somehow act on that. :-/ My gut feeling is that it's GHC, but I might be wrong...
S.