#12511: template-haskell's Language.Haskell.Syntax module should be Trustworthy -------------------------------------+------------------------------------- Reporter: int-e | Owner: Type: feature | Status: new request | Priority: normal | Milestone: Component: libraries | Version: 8.0.1 (other) | Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: None/Unknown Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- The reason why this module isn't inferred safe is that it uses `unsafePerformIO` to create a global `IORef`. From a SafeHaskell perspective, this module isn't very useful in itself, but its unsafety prevents other modules that import it to provide class instances from being inferred as safe. A concrete example is https://hackage.haskell.org/package/exceptions-0.8.3/docs/src/Control- Monad-Catch.html#line-186 -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/12511 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler