#13604: regression in ghc 8.2.1-rc1 (8.2.0.20170404) -------------------------------------+------------------------------------- Reporter: George | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: GHCi | Version: 8.2.1-rc1 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: Runtime | Unknown/Multiple performance bug | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by ezyang): So, the motivating principle for the change in behavior for `ghc --make` is that, if you run a `ghc` command, the end result should always be the same as if you had run GHC on a clean project. This means that, yes, if the optimization level changed, you better recompile your files. I don't think this is necessarily what GHCi users are looking for. Without `-fobject-code`, optimization level doesn't matter at all and I can definitely see an argument for the semantics, "Please ignore my flags and use the on-disk compiled products as much as possible, so long as they accurately reflect the source code of my program." This interpretation is supported by the fact that `-O` flag doesn't do anything right now. (But, it is probable that `-fobject-code` should shunt us back into the `--make` style semantics.) -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/13604#comment:11 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler