[[!comment format=mdwn username="picca" subject="comment 4" date="2015-09-30T13:06:46Z" content=""" In fact the real error meassage is this one. src/config.hs:166:17: Couldn't match expected type `RevertableProperty' with actual type `m0 a0' In the expression: withTmpDir \"sbuild\" $ \ tmpdir -> sbuild' system tmpdir In an equation for `sbuild': sbuild system = withTmpDir \"sbuild\" $ \ tmpdir -> sbuild' system tmpdir src/config.hs:166:50: Couldn't match expected type `m0 a0' with actual type `RevertableProperty' In the return type of a call of sbuild' In the expression: sbuild' system tmpdir In the second argument of `($)', namely `\ tmpdir -> sbuild' system tmpdir' """]]