haskell.packages.ghc94: revert to 9.4.2

Due to https://gitlab.haskell.org/ghc/ghc/-/issues/22425, we'll
tentatively stay with 9.4.2 for now. 9.4.3 is available explicitly
via haskell.packagse.ghc943 if you need it (e.g. on aarch64).

pkgs/development/compilers/ghc/9.4.2.nix

···
+# DO NOT port this expression to hadrian. It is not possible to build a GHC
+# cross compiler with 9.4.* and hadrian.
+{ lib, stdenv, pkgsBuildTarget, pkgsHostTarget, targetPackages
+
+# build-tools
+, bootPkgs
+, autoconf, automake, coreutils, fetchpatch, fetchurl, perl, python3, m4, sphinx
+, xattr, autoSignDarwinBinariesHook
+, bash
+
+, libiconv ? null, ncurses
+, glibcLocales ? null
+
+, # GHC can be built with system libffi or a bundled one.
+  libffi ? null
+
+, useLLVM ? !(stdenv.targetPlatform.isx86
+              || stdenv.targetPlatform.isPower
+              || stdenv.targetPlatform.isSparc
+              || (stdenv.targetPlatform.isAarch64 && stdenv.targetPlatform.isDarwin))
+, # LLVM is conceptually a run-time-only depedendency, but for
+  # non-x86, we need LLVM to bootstrap later stages, so it becomes a
+  # build-time dependency too.
+  buildTargetLlvmPackages, llvmPackages
+
+, # If enabled, GHC will be built with the GPL-free but slightly slower native
+  # bignum backend instead of the faster but GPLed gmp backend.
+  enableNativeBignum ? !(lib.meta.availableOn stdenv.hostPlatform gmp)
+, gmp
+
+, # If enabled, use -fPIC when compiling static libs.
+  enableRelocatedStaticLibs ? stdenv.targetPlatform != stdenv.hostPlatform
+
+  # aarch64 outputs otherwise exceed 2GB limit
+, enableProfiledLibs ? !stdenv.targetPlatform.isAarch64
+
+, # Whether to build dynamic libs for the standard library (on the target
+  # platform). Static libs are always built.
+  enableShared ? with stdenv.targetPlatform; !isWindows && !useiOSPrebuilt && !isStatic
+
+, # Whether to build terminfo.
+  enableTerminfo ? !stdenv.targetPlatform.isWindows
+
+, # What flavour to build. An empty string indicates no
+  # specific flavour and falls back to ghc default values.
+  ghcFlavour ? lib.optionalString (stdenv.targetPlatform != stdenv.hostPlatform)
+    (if useLLVM then "perf-cross" else "perf-cross-ncg")
+
+, #  Whether to build sphinx documentation.
+  enableDocs ? (
+    # Docs disabled for musl and cross because it's a large task to keep
+    # all `sphinx` dependencies building in those environments.
+    # `sphinx` pulls in among others:
+    # Ruby, Python, Perl, Rust, OpenGL, Xorg, gtk, LLVM.
+    (stdenv.targetPlatform == stdenv.hostPlatform)
+    && !stdenv.hostPlatform.isMusl
+  )
+
+, enableHaddockProgram ?
+    # Disabled for cross; see note [HADDOCK_DOCS].
+    (stdenv.targetPlatform == stdenv.hostPlatform)
+
+, # Whether to disable the large address space allocator
+  # necessary fix for iOS: https://www.reddit.com/r/haskell/comments/4ttdz1/building_an_osxi386_to_iosarm64_cross_compiler/d5qvd67/
+  disableLargeAddressSpace ? stdenv.targetPlatform.isiOS
+}:
+
+assert !enableNativeBignum -> gmp != null;
+
+# Cross cannot currently build the `haddock` program for silly reasons,
+# see note [HADDOCK_DOCS].
+assert (stdenv.targetPlatform != stdenv.hostPlatform) -> !enableHaddockProgram;
+
+let
+  inherit (stdenv) buildPlatform hostPlatform targetPlatform;
+
+  inherit (bootPkgs) ghc;
+
+  # TODO(@Ericson2314) Make unconditional
+  targetPrefix = lib.optionalString
+    (targetPlatform != hostPlatform)
+    "${targetPlatform.config}-";
+
+  buildMK = ''
+    BuildFlavour = ${ghcFlavour}
+    ifneq \"\$(BuildFlavour)\" \"\"
+    include mk/flavours/\$(BuildFlavour).mk
+    endif
+    BUILD_SPHINX_HTML = ${if enableDocs then "YES" else "NO"}
+    BUILD_SPHINX_PDF = NO
+  '' +
+  # Note [HADDOCK_DOCS]:
+  # Unfortunately currently `HADDOCK_DOCS` controls both whether the `haddock`
+  # program is built (which we generally always want to have a complete GHC install)
+  # and whether it is run on the GHC sources to generate hyperlinked source code
+  # (which is impossible for cross-compilation); see:
+  # https://gitlab.haskell.org/ghc/ghc/-/issues/20077
+  # This implies that currently a cross-compiled GHC will never have a `haddock`
+  # program, so it can never generate haddocks for any packages.
+  # If this is solved in the future, we'd like to unconditionally
+  # build the haddock program (removing the `enableHaddockProgram` option).
+  ''
+    HADDOCK_DOCS = ${if enableHaddockProgram then "YES" else "NO"}
+    # Build haddocks for boot packages with hyperlinking
+    EXTRA_HADDOCK_OPTS += --hyperlinked-source --quickjump
+
+    DYNAMIC_GHC_PROGRAMS = ${if enableShared then "YES" else "NO"}
+    BIGNUM_BACKEND = ${if enableNativeBignum then "native" else "gmp"}
+  '' + lib.optionalString (targetPlatform != hostPlatform) ''
+    Stage1Only = ${if targetPlatform.system == hostPlatform.system then "NO" else "YES"}
+    CrossCompilePrefix = ${targetPrefix}
+  '' + lib.optionalString (!enableProfiledLibs) ''
+    GhcLibWays = "v dyn"
+  '' +
+  # -fexternal-dynamic-refs apparently (because it's not clear from the documentation)
+  # makes the GHC RTS able to load static libraries, which may be needed for TemplateHaskell.
+  # This solution was described in https://www.tweag.io/blog/2020-09-30-bazel-static-haskell
+  lib.optionalString enableRelocatedStaticLibs ''
+    GhcLibHcOpts += -fPIC -fexternal-dynamic-refs
+    GhcRtsHcOpts += -fPIC -fexternal-dynamic-refs
+  '' + lib.optionalString targetPlatform.useAndroidPrebuilt ''
+    EXTRA_CC_OPTS += -std=gnu99
+  '';
+
+  # Splicer will pull out correct variations
+  libDeps = platform: lib.optional enableTerminfo ncurses
+    ++ [libffi]
+    ++ lib.optional (!enableNativeBignum) gmp
+    ++ lib.optional (platform.libc != "glibc" && !targetPlatform.isWindows) libiconv;
+
+  # TODO(@sternenseemann): is buildTarget LLVM unnecessary?
+  # GHC doesn't seem to have {LLC,OPT}_HOST
+  toolsForTarget = [
+    pkgsBuildTarget.targetPackages.stdenv.cc
+  ] ++ lib.optional useLLVM buildTargetLlvmPackages.llvm;
+
+  targetCC = builtins.head toolsForTarget;
+
+  # Sometimes we have to dispatch between the bintools wrapper and the unwrapped
+  # derivation for certain tools depending on the platform.
+  bintoolsFor = {
+    # GHC needs install_name_tool on all darwin platforms. On aarch64-darwin it is
+    # part of the bintools wrapper (due to codesigning requirements), but not on
+    # x86_64-darwin.
+    install_name_tool =
+      if stdenv.targetPlatform.isAarch64
+      then targetCC.bintools
+      else targetCC.bintools.bintools;
+    # Same goes for strip.
+    strip =
+      # TODO(@sternenseemann): also use wrapper if linker == "bfd" or "gold"
+      if stdenv.targetPlatform.isAarch64 && stdenv.targetPlatform.isDarwin
+      then targetCC.bintools
+      else targetCC.bintools.bintools;
+  };
+
+  # Use gold either following the default, or to avoid the BFD linker due to some bugs / perf issues.
+  # But we cannot avoid BFD when using musl libc due to https://sourceware.org/bugzilla/show_bug.cgi?id=23856
+  # see #84670 and #49071 for more background.
+  useLdGold = targetPlatform.linker == "gold" ||
+    (targetPlatform.linker == "bfd" && (targetCC.bintools.bintools.hasGold or false) && !targetPlatform.isMusl);
+
+  # Makes debugging easier to see which variant is at play in `nix-store -q --tree`.
+  variantSuffix = lib.concatStrings [
+    (lib.optionalString stdenv.hostPlatform.isMusl "-musl")
+    (lib.optionalString enableNativeBignum "-native-bignum")
+  ];
+
+in
+
+# C compiler, bintools and LLVM are used at build time, but will also leak into
+# the resulting GHC's settings file and used at runtime. This means that we are
+# currently only able to build GHC if hostPlatform == buildPlatform.
+assert targetCC == pkgsHostTarget.targetPackages.stdenv.cc;
+assert buildTargetLlvmPackages.llvm == llvmPackages.llvm;
+assert stdenv.targetPlatform.isDarwin -> buildTargetLlvmPackages.clang == llvmPackages.clang;
+
+stdenv.mkDerivation (rec {
+  version = "9.4.2";
+  pname = "${targetPrefix}ghc${variantSuffix}";
+
+  src = fetchurl {
+    url = "https://downloads.haskell.org/ghc/${version}/ghc-${version}-src.tar.xz";
+    sha256 = "7227ef3b5e15a0d70b8f1a43aec32867e2a9b2d857cc0ed556aeed172d4db3a5";
+  };
+
+  enableParallelBuilding = true;
+
+  outputs = [ "out" "doc" ];
+
+
+  postPatch = "patchShebangs .";
+
+  # GHC needs the locale configured during the Haddock phase.
+  LANG = "en_US.UTF-8";
+
+  # GHC is a bit confused on its cross terminology.
+  # TODO(@sternenseemann): investigate coreutils dependencies and pass absolute paths
+  preConfigure = ''
+    for env in $(env | grep '^TARGET_' | sed -E 's|\+?=.*||'); do
+      export "''${env#TARGET_}=''${!env}"
+    done
+    # GHC is a bit confused on its cross terminology, as these would normally be
+    # the *host* tools.
+    export CC="${targetCC}/bin/${targetCC.targetPrefix}cc"
+    export CXX="${targetCC}/bin/${targetCC.targetPrefix}c++"
+    # Use gold to work around https://sourceware.org/bugzilla/show_bug.cgi?id=16177
+    export LD="${targetCC.bintools}/bin/${targetCC.bintools.targetPrefix}ld${lib.optionalString useLdGold ".gold"}"
+    export AS="${targetCC.bintools.bintools}/bin/${targetCC.bintools.targetPrefix}as"
+    export AR="${targetCC.bintools.bintools}/bin/${targetCC.bintools.targetPrefix}ar"
+    export NM="${targetCC.bintools.bintools}/bin/${targetCC.bintools.targetPrefix}nm"
+    export RANLIB="${targetCC.bintools.bintools}/bin/${targetCC.bintools.targetPrefix}ranlib"
+    export READELF="${targetCC.bintools.bintools}/bin/${targetCC.bintools.targetPrefix}readelf"
+    export STRIP="${bintoolsFor.strip}/bin/${bintoolsFor.strip.targetPrefix}strip"
+  '' + lib.optionalString (stdenv.targetPlatform.linker == "cctools") ''
+    export OTOOL="${targetCC.bintools.bintools}/bin/${targetCC.bintools.targetPrefix}otool"
+    export INSTALL_NAME_TOOL="${bintoolsFor.install_name_tool}/bin/${bintoolsFor.install_name_tool.targetPrefix}install_name_tool"
+  '' + lib.optionalString useLLVM ''
+    export LLC="${lib.getBin buildTargetLlvmPackages.llvm}/bin/llc"
+    export OPT="${lib.getBin buildTargetLlvmPackages.llvm}/bin/opt"
+  '' + lib.optionalString (useLLVM && stdenv.targetPlatform.isDarwin) ''
+    # LLVM backend on Darwin needs clang: https://downloads.haskell.org/~ghc/latest/docs/html/users_guide/codegens.html#llvm-code-generator-fllvm
+    export CLANG="${buildTargetLlvmPackages.clang}/bin/${buildTargetLlvmPackages.clang.targetPrefix}clang"
+  '' + ''
+
+    echo -n "${buildMK}" > mk/build.mk
+
+    sed -i -e 's|-isysroot /Developer/SDKs/MacOSX10.5.sdk||' configure
+  '' + lib.optionalString (stdenv.isLinux && hostPlatform.libc == "glibc") ''
+    export LOCALE_ARCHIVE="${glibcLocales}/lib/locale/locale-archive"
+  '' + lib.optionalString (!stdenv.isDarwin) ''
+    export NIX_LDFLAGS+=" -rpath $out/lib/ghc-${version}"
+  '' + lib.optionalString stdenv.isDarwin ''
+    export NIX_LDFLAGS+=" -no_dtrace_dof"
+
+    # GHC tries the host xattr /usr/bin/xattr by default which fails since it expects python to be 2.7
+    export XATTR=${lib.getBin xattr}/bin/xattr
+  '' + lib.optionalString targetPlatform.useAndroidPrebuilt ''
+    sed -i -e '5i ,("armv7a-unknown-linux-androideabi", ("e-m:e-p:32:32-i64:64-v128:64:128-a:0:32-n32-S64", "cortex-a8", ""))' llvm-targets
+  '' + lib.optionalString targetPlatform.isMusl ''
+      echo "patching llvm-targets for musl targets..."
+      echo "Cloning these existing '*-linux-gnu*' targets:"
+      grep linux-gnu llvm-targets | sed 's/^/  /'
+      echo "(go go gadget sed)"
+      sed -i 's,\(^.*linux-\)gnu\(.*\)$,\0\n\1musl\2,' llvm-targets
+      echo "llvm-targets now contains these '*-linux-musl*' targets:"
+      grep linux-musl llvm-targets | sed 's/^/  /'
+
+      echo "And now patching to preserve '-musleabi' as done with '-gnueabi'"
+      # (aclocal.m4 is actual source, but patch configure as well since we don't re-gen)
+      for x in configure aclocal.m4; do
+        substituteInPlace $x \
+          --replace '*-android*|*-gnueabi*)' \
+                    '*-android*|*-gnueabi*|*-musleabi*)'
+      done
+  ''
+  # HACK: allow bootstrapping with GHC 8.10 which works fine, as we don't have
+  # binary 9.0 packaged. Bootstrapping with 9.2 is broken without hadrian.
+  + ''
+    substituteInPlace configure --replace \
+      'MinBootGhcVersion="9.0"' \
+      'MinBootGhcVersion="8.10"'
+  '';
+
+  # TODO(@Ericson2314): Always pass "--target" and always prefix.
+  configurePlatforms = [ "build" "host" ]
+    ++ lib.optional (targetPlatform != hostPlatform) "target";
+
+  # `--with` flags for libraries needed for RTS linker
+  configureFlags = [
+    "--datadir=$doc/share/doc/ghc"
+    "--with-curses-includes=${ncurses.dev}/include" "--with-curses-libraries=${ncurses.out}/lib"
+  ] ++ lib.optionals (libffi != null) [
+    "--with-system-libffi"
+    "--with-ffi-includes=${targetPackages.libffi.dev}/include"
+    "--with-ffi-libraries=${targetPackages.libffi.out}/lib"
+  ] ++ lib.optionals (targetPlatform == hostPlatform && !enableNativeBignum) [
+    "--with-gmp-includes=${targetPackages.gmp.dev}/include"
+    "--with-gmp-libraries=${targetPackages.gmp.out}/lib"
+  ] ++ lib.optionals (targetPlatform == hostPlatform && hostPlatform.libc != "glibc" && !targetPlatform.isWindows) [
+    "--with-iconv-includes=${libiconv}/include"
+    "--with-iconv-libraries=${libiconv}/lib"
+  ] ++ lib.optionals (targetPlatform != hostPlatform) [
+    "--enable-bootstrap-with-devel-snapshot"
+  ] ++ lib.optionals useLdGold [
+    "CFLAGS=-fuse-ld=gold"
+    "CONF_GCC_LINKER_OPTS_STAGE1=-fuse-ld=gold"
+    "CONF_GCC_LINKER_OPTS_STAGE2=-fuse-ld=gold"
+  ] ++ lib.optionals (disableLargeAddressSpace) [
+    "--disable-large-address-space"
+  ];
+
+  # Make sure we never relax`$PATH` and hooks support for compatibility.
+  strictDeps = true;
+
+  # Don’t add -liconv to LDFLAGS automatically so that GHC will add it itself.
+  dontAddExtraLibs = true;
+
+  nativeBuildInputs = [
+    perl autoconf automake m4 python3
+    ghc bootPkgs.alex bootPkgs.happy bootPkgs.hscolour
+  ] ++ lib.optionals (stdenv.isDarwin && stdenv.isAarch64) [
+    autoSignDarwinBinariesHook
+  ] ++ lib.optionals enableDocs [
+    sphinx
+  ];
+
+  # For building runtime libs
+  depsBuildTarget = toolsForTarget;
+
+  buildInputs = [ perl bash ] ++ (libDeps hostPlatform);
+
+  depsTargetTarget = map lib.getDev (libDeps targetPlatform);
+  depsTargetTargetPropagated = map (lib.getOutput "out") (libDeps targetPlatform);
+
+  # required, because otherwise all symbols from HSffi.o are stripped, and
+  # that in turn causes GHCi to abort
+  stripDebugFlags = [ "-S" ] ++ lib.optional (!targetPlatform.isDarwin) "--keep-file-symbols";
+
+  checkTarget = "test";
+
+  hardeningDisable =
+    [ "format" ]
+    # In nixpkgs, musl based builds currently enable `pie` hardening by default
+    # (see `defaultHardeningFlags` in `make-derivation.nix`).
+    # But GHC cannot currently produce outputs that are ready for `-pie` linking.
+    # Thus, disable `pie` hardening, otherwise `recompile with -fPIE` errors appear.
+    # See:
+    # * https://github.com/NixOS/nixpkgs/issues/129247
+    # * https://gitlab.haskell.org/ghc/ghc/-/issues/19580
+    ++ lib.optional stdenv.targetPlatform.isMusl "pie";
+
+  # big-parallel allows us to build with more than 2 cores on
+  # Hydra which already warrants a significant speedup
+  requiredSystemFeatures = [ "big-parallel" ];
+
+  postInstall = ''
+    # Install the bash completion file.
+    install -D -m 444 utils/completion/ghc.bash $out/share/bash-completion/completions/${targetPrefix}ghc
+  '';
+
+  passthru = {
+    inherit bootPkgs targetPrefix;
+
+    inherit llvmPackages;
+    inherit enableShared;
+
+    # This is used by the haskell builder to query
+    # the presence of the haddock program.
+    hasHaddock = enableHaddockProgram;
+
+    # Our Cabal compiler name
+    haskellCompilerName = "ghc-${version}";
+  };
+
+  meta = {
+    homepage = "http://haskell.org/ghc";
+    description = "The Glasgow Haskell Compiler";
+    maintainers = with lib.maintainers; [
+      guibou
+    ] ++ lib.teams.haskell.members;
+    timeout = 24 * 3600;
+    inherit (ghc.meta) license platforms;
+  };
+
+} // lib.optionalAttrs targetPlatform.useAndroidPrebuilt {
+  dontStrip = true;
+  dontPatchELF = true;
+  noAuditTmpdir = true;
+})

pkgs/top-level/haskell-packages.nix

···
     "ghc924"
     "ghc925"
     "ghc92"
+    "ghc942"
     "ghc943"
     "ghc94"
     "ghcHEAD"
···
     "ghc924"
     "ghc925"
     "ghc94"
+    "ghc942"
     "ghc943"
     "ghcHEAD"
   ];
···
       llvmPackages = pkgs.llvmPackages_12;
     };
     ghc92 = ghc925;
+    ghc942 = callPackage ../development/compilers/ghc/9.4.2.nix {
+      bootPkgs =
+        # Building with 9.2 is broken due to
+        # https://gitlab.haskell.org/ghc/ghc/-/issues/21914
+        # Use 8.10 as a workaround where possible to keep bootstrap path short.
+
+        # On ARM text won't build with GHC 8.10.*
+        if stdenv.hostPlatform.isAarch then
+          # TODO(@sternenseemann): package bindist
+          packages.ghc902
+        # No suitable bindists for powerpc64le
+        else if stdenv.hostPlatform.isPower64 && stdenv.hostPlatform.isLittleEndian then
+          packages.ghc902
+        else
+          packages.ghc8107Binary;
+      inherit (buildPackages.python3Packages) sphinx;
+      # Need to use apple's patched xattr until
+      # https://github.com/xattr/xattr/issues/44 and
+      # https://github.com/xattr/xattr/issues/55 are solved.
+      inherit (buildPackages.darwin) xattr autoSignDarwinBinariesHook;
+      # Support range >= 10 && < 14
+      buildTargetLlvmPackages = pkgsBuildTarget.llvmPackages_12;
+      llvmPackages = pkgs.llvmPackages_12;
+    };
     ghc943 = callPackage ../development/compilers/ghc/9.4.3.nix {
       bootPkgs =
         # Building with 9.2 is broken due to
···
       buildTargetLlvmPackages = pkgsBuildTarget.llvmPackages_12;
       llvmPackages = pkgs.llvmPackages_12;
     };
-    ghc94 = ghc943;
+    ghc94 = ghc942;
     ghcHEAD = callPackage ../development/compilers/ghc/head.nix {
       bootPkgs =
         # For GHC 9.2 no armv7l bindists are available.
···
       compilerConfig = callPackage ../development/haskell-modules/configuration-ghc-9.2.x.nix { };
     };
     ghc92 = ghc925;
+    ghc942 = callPackage ../development/haskell-modules {
+      buildHaskellPackages = bh.packages.ghc942;
+      ghc = bh.compiler.ghc942;
+      compilerConfig = callPackage ../development/haskell-modules/configuration-ghc-9.4.x.nix { };
+    };
     ghc943 = callPackage ../development/haskell-modules {
       buildHaskellPackages = bh.packages.ghc943;
       ghc = bh.compiler.ghc943;
       compilerConfig = callPackage ../development/haskell-modules/configuration-ghc-9.4.x.nix { };
     };
-    ghc94 = ghc943;
+    ghc94 = ghc942;
     ghcHEAD = callPackage ../development/haskell-modules {
       buildHaskellPackages = bh.packages.ghcHEAD;
       ghc = bh.compiler.ghcHEAD;

pkgs/top-level/release-haskell.nix

···
     ghc8107
     ghc902
     ghc925
+    ghc942
     ghc943
   ];