Merge pull request #810 from reflex-frp/dylang/fix-macos

Add patches to fix GHC 8.6.5 on MacOS Big Sur and up

default.nix

@@ -42,6 +42,8 @@ let iosSupport = system == "x86_64-darwin";
               # nixpkgs-21.05 ships with a version of autoreconf that is incompatible with ghc 8.6.5,
               # Cf. https://gitlab.haskell.org/ghc/ghc/-/commit/ad2ef3a13f1eb000eab8e3d64592373b91a52806
               ./haskell-overlays/splices-load-save/ghc-8.6-autoreconf.patch
+            ] ++ super.lib.optionals (super.stdenv.targetPlatform.isDarwin) [
+              ./haskell-overlays/patches/ghc865/fix-big-sur.patch
             ];
           })).override {
             bootPkgs = super.haskell.packages.ghc865Binary // {
@@ -128,6 +130,7 @@ let iosSupport = system == "x86_64-darwin";
           binutils-unwrapped = super.binutils-unwrapped.override {
             autoreconfHook = lib.optional self.stdenv.buildPlatform.isDarwin super.autoreconfHook269;
           };
+
           # Bump ios-deploy
           # - for faster deployments
           # - fixes debug deploy with iOS 16/macos 12.3/ xcode 13.4.1

haskell-overlays/patches/ghc865/fix-big-sur.patch

@@ -0,0 +1,80 @@
+diff --git a/compiler/ghci/Linker.hs b/compiler/ghci/Linker.hs
+index dbe71cd9ab048bd5cc9b2774dd30faeecbdd84fb..da18c019461bdffd62e06bd0441742786109c08c 100644
+--- a/compiler/ghci/Linker.hs
++++ b/compiler/ghci/Linker.hs
+@@ -1676,6 +1676,38 @@ addEnvPaths name list
+ -- ----------------------------------------------------------------------------
+ -- Loading a dynamic library (dlopen()-ish on Unix, LoadLibrary-ish on Win32)
+
++{-
++Note [macOS Big Sur dynamic libraries]
++~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
++
++macOS Big Sur makes the following change to how frameworks are shipped
++with the OS:
++
++> New in macOS Big Sur 11 beta, the system ships with a built-in
++> dynamic linker cache of all system-provided libraries.  As part of
++> this change, copies of dynamic libraries are no longer present on
++> the filesystem.  Code that attempts to check for dynamic library
++> presence by looking for a file at a path or enumerating a directory
++> will fail.  Instead, check for library presence by attempting to
++> dlopen() the path, which will correctly check for the library in the
++> cache. (62986286)
++
++(https://developer.apple.com/documentation/macos-release-notes/macos-big-sur-11_0_1-release-notes/)
++
++Therefore, the previous method of checking whether a library exists
++before attempting to load it makes GHC.Runtime.Linker.loadFramework
++fail to find frameworks installed at /System/Library/Frameworks.
++Instead, any attempt to load a framework at runtime, such as by
++passing -framework OpenGL to runghc or running code loading such a
++framework with GHCi, fails with a 'not found' message.
++
++GHC.Runtime.Linker.loadFramework now opportunistically loads the
++framework libraries without checking for their existence first,
++failing only if all attempts to load a given framework from any of the
++various possible locations fail.  See also #18446, which this change
++addresses.
++-}
++
+ -- Darwin / MacOS X only: load a framework
+ -- a framework is a dynamic library packaged inside a directory of the same
+ -- name. They are searched for in different paths than normal libraries.
+@@ -1686,17 +1718,29 @@ loadFramework hsc_env extraPaths rootname
+                                   Left _ -> []
+                                   Right dir -> [dir </> "Library/Frameworks"]
+               ps = extraPaths ++ homeFrameworkPath ++ defaultFrameworkPaths
+-        ; mb_fwk <- findFile ps fwk_file
+-        ; case mb_fwk of
+-            Just fwk_path -> loadDLL hsc_env fwk_path
+-            Nothing       -> return (Just "not found") }
+-                -- Tried all our known library paths, but dlopen()
+-                -- has no built-in paths for frameworks: give up
++        ; errs <- findLoadDLL ps []
++        ; return $ fmap (intercalate ", ") errs
++        }
+    where
+      fwk_file = rootname <.> "framework" </> rootname
+-        -- sorry for the hardcoded paths, I hope they won't change anytime soon:
++
++     -- sorry for the hardcoded paths, I hope they won't change anytime soon:
+      defaultFrameworkPaths = ["/Library/Frameworks", "/System/Library/Frameworks"]
+
++     -- Try to call loadDLL for each candidate path.
++     --
++     -- See Note [macOS Big Sur dynamic libraries]
++     findLoadDLL [] errs =
++       -- Tried all our known library paths, but dlopen()
++       -- has no built-in paths for frameworks: give up
++       return $ Just errs
++     findLoadDLL (p:ps) errs =
++       do { dll <- loadDLL hsc_env (p </> fwk_file)
++          ; case dll of
++              Nothing  -> return Nothing
++              Just err -> findLoadDLL ps ((p ++ ": " ++ err):errs)
++          }
++
+ {- **********************************************************************
+
+                 Helper functions