diff --git a/pkgs/development/compilers/ghc/8.10.7.nix b/pkgs/development/compilers/ghc/8.10.7.nix
index 4a770d993a678..c2dcf2bad1966 100644
--- a/pkgs/development/compilers/ghc/8.10.7.nix
+++ b/pkgs/development/compilers/ghc/8.10.7.nix
@@ -1,8 +1,8 @@
-{ lib, stdenv, pkgsBuildTarget, pkgsHostTarget, targetPackages
+{ lib, stdenv, pkgsBuildTarget, pkgsHostTarget, buildPackages, targetPackages
 
 # build-tools
 , bootPkgs
-, autoconf, automake, coreutils, fetchpatch, fetchurl, perl, python3, m4, sphinx
+, autoreconfHook, autoconf, automake, coreutils, fetchpatch, fetchurl, perl, python3, m4, sphinx
 , xattr, autoSignDarwinBinariesHook
 , bash
 
@@ -44,25 +44,35 @@
 
 , #  Whether to build sphinx documentation.
   enableDocs ? (
-    # Docs disabled if we are building on musl because it's a large task to keep
-    # all `sphinx` dependencies building in this environment.
-    !stdenv.buildPlatform.isMusl
+    # Docs disabled if we are building on musl or cross-building because it's a
+    # large task to keep all `sphinx` dependencies building in this environment.
+    (stdenv.buildPlatform == stdenv.hostPlatform && stdenv.targetPlatform == stdenv.hostPlatform)
+    && !stdenv.buildPlatform.isMusl
   )
 
 , enableHaddockProgram ?
     # Disabled for cross; see note [HADDOCK_DOCS].
-    (stdenv.targetPlatform == stdenv.hostPlatform)
+    (stdenv.buildPlatform == stdenv.hostPlatform && 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
+
+, # Whether to build an unregisterised version of GHC.
+  # GHC will normally auto-detect whether it can do a registered build, but this
+  # option will force it to do an unregistered build when set to true.
+  # See https://gitlab.haskell.org/ghc/ghc/-/wikis/building/unregisterised
+  enableUnregisterised ? false
 }:
 
 assert !enableIntegerSimple -> gmp != null;
 
 # Cross cannot currently build the `haddock` program for silly reasons,
 # see note [HADDOCK_DOCS].
-assert (stdenv.targetPlatform != stdenv.hostPlatform) -> !enableHaddockProgram;
+assert (stdenv.buildPlatform != stdenv.hostPlatform || stdenv.targetPlatform != stdenv.hostPlatform) -> !enableHaddockProgram;
+
+# GHC does not support building when all 3 platforms are different.
+assert stdenv.buildPlatform == stdenv.hostPlatform || stdenv.hostPlatform == stdenv.targetPlatform;
 
 let
   inherit (stdenv) buildPlatform hostPlatform targetPlatform;
@@ -129,7 +139,9 @@ let
     pkgsBuildTarget.targetPackages.stdenv.cc
   ] ++ lib.optional useLLVM buildTargetLlvmPackages.llvm;
 
+  buildCC = buildPackages.stdenv.cc;
   targetCC = builtins.head toolsForTarget;
+  installCC = pkgsHostTarget.targetPackages.stdenv.cc;
 
   # Sometimes we have to dispatch between the bintools wrapper and the unwrapped
   # derivation for certain tools depending on the platform.
@@ -161,14 +173,11 @@ let
     (lib.optionalString enableIntegerSimple "-integer-simple")
   ];
 
-in
+  targetLibffi = if hostPlatform != targetPlatform
+    then targetPackages.libffi
+    else pkgsHostTarget.libffi;
 
-# 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;
+in
 
 stdenv.mkDerivation (rec {
   version = "8.10.7";
@@ -223,6 +232,12 @@ stdenv.mkDerivation (rec {
       stripLen = 3;
       extraPrefix = "libraries/Cabal/Cabal/";
     })
+
+    # We need to be able to set AR_STAGE0 and LD_STAGE0 when cross-compiling
+    (fetchpatch {
+      url = "https://gitlab.haskell.org/ghc/ghc/-/commit/8f7dd5710b80906ea7a3e15b7bb56a883a49fed8.patch";
+      hash = "sha256-C636Nq2U8YOG/av7XQmG3L1rU0bmC9/7m7Hty5pm5+s=";
+    })
   ] ++ lib.optionals stdenv.isDarwin [
     # Make Block.h compile with c++ compilers. Remove with the next release
     (fetchpatch {
@@ -241,6 +256,9 @@ stdenv.mkDerivation (rec {
 
   postPatch = "patchShebangs .";
 
+  # GHC is unable to build a cross-compiler without this set.
+  "NIX_CC_WRAPPER_TARGET_HOST_${buildCC.suffixSalt}" = 1;
+
   # GHC is a bit confused on its cross terminology.
   # TODO(@sternenseemann): investigate coreutils dependencies and pass absolute paths
   preConfigure = ''
@@ -269,6 +287,9 @@ stdenv.mkDerivation (rec {
     # LLVM backend on Darwin needs clang: https://downloads.haskell.org/~ghc/latest/docs/html/users_guide/codegens.html#llvm-code-generator-fllvm
     export CLANG="${buildTargetLlvmPackages.clang}/bin/${buildTargetLlvmPackages.clang.targetPrefix}clang"
   '' + ''
+    export CC_STAGE0="${buildCC}/bin/${buildCC.targetPrefix}cc"
+    export LD_STAGE0="${buildCC.bintools}/bin/${buildCC.bintools.targetPrefix}ld"
+    export AR_STAGE0="${buildCC.bintools.bintools}/bin/${buildCC.bintools.targetPrefix}ar"
 
     echo -n "${buildMK}" > mk/build.mk
     sed -i -e 's|-isysroot /Developer/SDKs/MacOSX10.5.sdk||' configure
@@ -299,18 +320,22 @@ stdenv.mkDerivation (rec {
       done
   '';
 
+  # Although it is usually correct to pass --host, we don't do that here because
+  # GHC's usage of build, host, and target is non-standard.
+  # See https://gitlab.haskell.org/ghc/ghc/-/wikis/building/cross-compiling
   # TODO(@Ericson2314): Always pass "--target" and always prefix.
-  configurePlatforms = [ "build" "host" ]
-    ++ lib.optional (targetPlatform != hostPlatform) "target";
+  configurePlatforms = [ "build" ]
+    ++ lib.optional (buildPlatform != hostPlatform || 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=${ncurses.out}/lib"
+    "--with-curses-includes=${buildPackages.ncurses.dev}/include"
+    "--with-curses-libraries=${buildPackages.ncurses.out}/lib"
   ] ++ lib.optionals (libffi != null) [
     "--with-system-libffi"
-    "--with-ffi-includes=${targetPackages.libffi.dev}/include"
-    "--with-ffi-libraries=${targetPackages.libffi.out}/lib"
+    "--with-ffi-includes=${targetLibffi.dev}/include"
+    "--with-ffi-libraries=${targetLibffi.out}/lib"
   ] ++ lib.optionals (targetPlatform == hostPlatform && !enableIntegerSimple) [
     "--with-gmp-includes=${targetPackages.gmp.dev}/include"
     "--with-gmp-libraries=${targetPackages.gmp.out}/lib"
@@ -325,6 +350,8 @@ stdenv.mkDerivation (rec {
     "CONF_GCC_LINKER_OPTS_STAGE2=-fuse-ld=gold"
   ] ++ lib.optionals (disableLargeAddressSpace) [
     "--disable-large-address-space"
+  ] ++ lib.optionals enableUnregisterised [
+    "--enable-unregisterised"
   ];
 
   # Make sure we never relax`$PATH` and hooks support for compatibility.
@@ -334,7 +361,7 @@ stdenv.mkDerivation (rec {
   dontAddExtraLibs = true;
 
   nativeBuildInputs = [
-    perl autoconf automake m4 python3
+    perl autoreconfHook autoconf automake m4 python3
     ghc bootPkgs.alex bootPkgs.happy bootPkgs.hscolour
   ] ++ lib.optionals (stdenv.isDarwin && stdenv.isAarch64) [
     autoSignDarwinBinariesHook
@@ -372,6 +399,14 @@ stdenv.mkDerivation (rec {
   requiredSystemFeatures = [ "big-parallel" ];
 
   postInstall = ''
+    # Make the installed GHC use the host platform's tools.
+    sed -i $out/lib/${targetPrefix}${passthru.haskellCompilerName}/settings \
+      -e "s!$CC!${installCC}/bin/${installCC.targetPrefix}cc!g" \
+      -e "s!$CXX!${installCC}/bin/${installCC.targetPrefix}c++!g" \
+      -e "s!$LD!${installCC.bintools}/bin/${installCC.bintools.targetPrefix}ld${lib.optionalString useLdGold ".gold"}!g" \
+      -e "s!$AR!${installCC.bintools.bintools}/bin/${installCC.bintools.targetPrefix}ar!g" \
+      -e "s!$RANLIB!${installCC.bintools.bintools}/bin/${installCC.bintools.targetPrefix}ranlib!g"
+
     # Install the bash completion file.
     install -D -m 444 utils/completion/ghc.bash $out/share/bash-completion/completions/${targetPrefix}ghc
   '';
@@ -397,7 +432,8 @@ stdenv.mkDerivation (rec {
       guibou
     ] ++ lib.teams.haskell.members;
     timeout = 24 * 3600;
-    inherit (ghc.meta) license platforms;
+    platforms = lib.platforms.all;
+    inherit (ghc.meta) license;
   };
 
 } // lib.optionalAttrs targetPlatform.useAndroidPrebuilt {
diff --git a/pkgs/development/compilers/ghc/9.0.2.nix b/pkgs/development/compilers/ghc/9.0.2.nix
index 175d1fe2450b7..4080798154a79 100644
--- a/pkgs/development/compilers/ghc/9.0.2.nix
+++ b/pkgs/development/compilers/ghc/9.0.2.nix
@@ -1,4 +1,4 @@
-{ lib, stdenv, pkgsBuildTarget, pkgsHostTarget, targetPackages
+{ lib, stdenv, pkgsBuildTarget, pkgsHostTarget, buildPackages, targetPackages
 
 # build-tools
 , bootPkgs
@@ -46,25 +46,35 @@
 
 , #  Whether to build sphinx documentation.
   enableDocs ? (
-    # Docs disabled if we are building on musl because it's a large task to keep
-    # all `sphinx` dependencies building in this environment.
-    !stdenv.buildPlatform.isMusl
+    # Docs disabled if we are building on musl or cross-building because it's a
+    # large task to keep all `sphinx` dependencies building in this environment.
+    (stdenv.buildPlatform == stdenv.hostPlatform && stdenv.targetPlatform == stdenv.hostPlatform)
+    && !stdenv.buildPlatform.isMusl
   )
 
 , enableHaddockProgram ?
     # Disabled for cross; see note [HADDOCK_DOCS].
-    (stdenv.targetPlatform == stdenv.hostPlatform)
+    (stdenv.buildPlatform == stdenv.hostPlatform && 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
+
+, # Whether to build an unregisterised version of GHC.
+  # GHC will normally auto-detect whether it can do a registered build, but this
+  # option will force it to do an unregistered build when set to true.
+  # See https://gitlab.haskell.org/ghc/ghc/-/wikis/building/unregisterised
+  enableUnregisterised ? false
 }:
 
 assert !enableNativeBignum -> gmp != null;
 
 # Cross cannot currently build the `haddock` program for silly reasons,
 # see note [HADDOCK_DOCS].
-assert (stdenv.targetPlatform != stdenv.hostPlatform) -> !enableHaddockProgram;
+assert (stdenv.buildPlatform != stdenv.hostPlatform || stdenv.targetPlatform != stdenv.hostPlatform) -> !enableHaddockProgram;
+
+# GHC does not support building when all 3 platforms are different.
+assert stdenv.buildPlatform == stdenv.hostPlatform || stdenv.hostPlatform == stdenv.targetPlatform;
 
 let
   inherit (stdenv) buildPlatform hostPlatform targetPlatform;
@@ -129,7 +139,9 @@ let
     pkgsBuildTarget.targetPackages.stdenv.cc
   ] ++ lib.optional useLLVM buildTargetLlvmPackages.llvm;
 
+  buildCC = buildPackages.stdenv.cc;
   targetCC = builtins.head toolsForTarget;
+  installCC = pkgsHostTarget.targetPackages.stdenv.cc;
 
   # Sometimes we have to dispatch between the bintools wrapper and the unwrapped
   # derivation for certain tools depending on the platform.
@@ -161,14 +173,11 @@ let
     (lib.optionalString enableNativeBignum "-native-bignum")
   ];
 
-in
+  targetLibffi = if hostPlatform != targetPlatform
+    then targetPackages.libffi
+    else pkgsHostTarget.libffi;
 
-# 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;
+in
 
 stdenv.mkDerivation (rec {
   version = "9.0.2";
@@ -224,6 +233,9 @@ stdenv.mkDerivation (rec {
   # GHC needs the locale configured during the Haddock phase.
   LANG = "en_US.UTF-8";
 
+  # GHC is unable to build a cross-compiler without this set.
+  "NIX_CC_WRAPPER_TARGET_HOST_${buildCC.suffixSalt}" = 1;
+
   # GHC is a bit confused on its cross terminology.
   # TODO(@sternenseemann): investigate coreutils dependencies and pass absolute paths
   preConfigure = ''
@@ -252,6 +264,9 @@ stdenv.mkDerivation (rec {
     # LLVM backend on Darwin needs clang: https://downloads.haskell.org/~ghc/latest/docs/html/users_guide/codegens.html#llvm-code-generator-fllvm
     export CLANG="${buildTargetLlvmPackages.clang}/bin/${buildTargetLlvmPackages.clang.targetPrefix}clang"
   '' + ''
+    export CC_STAGE0="${buildCC}/bin/${buildCC.targetPrefix}cc"
+    export LD_STAGE0="${buildCC.bintools}/bin/${buildCC.bintools.targetPrefix}ld"
+    export AR_STAGE0="${buildCC.bintools.bintools}/bin/${buildCC.bintools.targetPrefix}ar"
 
     echo -n "${buildMK}" > mk/build.mk
     sed -i -e 's|-isysroot /Developer/SDKs/MacOSX10.5.sdk||' configure
@@ -281,18 +296,22 @@ stdenv.mkDerivation (rec {
       done
   '';
 
+  # Although it is usually correct to pass --host, we don't do that here because
+  # GHC's usage of build, host, and target is non-standard.
+  # See https://gitlab.haskell.org/ghc/ghc/-/wikis/building/cross-compiling
   # TODO(@Ericson2314): Always pass "--target" and always prefix.
-  configurePlatforms = [ "build" "host" ]
-    ++ lib.optional (targetPlatform != hostPlatform) "target";
+  configurePlatforms = [ "build" ]
+    ++ lib.optional (buildPlatform != hostPlatform || 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=${ncurses.out}/lib"
+    "--with-curses-includes=${buildPackages.ncurses.dev}/include"
+    "--with-curses-libraries=${buildPackages.ncurses.out}/lib"
   ] ++ lib.optionals (libffi != null) [
     "--with-system-libffi"
-    "--with-ffi-includes=${targetPackages.libffi.dev}/include"
-    "--with-ffi-libraries=${targetPackages.libffi.out}/lib"
+    "--with-ffi-includes=${targetLibffi.dev}/include"
+    "--with-ffi-libraries=${targetLibffi.out}/lib"
   ] ++ lib.optionals (targetPlatform == hostPlatform && !enableNativeBignum) [
     "--with-gmp-includes=${targetPackages.gmp.dev}/include"
     "--with-gmp-libraries=${targetPackages.gmp.out}/lib"
@@ -307,6 +326,8 @@ stdenv.mkDerivation (rec {
     "CONF_GCC_LINKER_OPTS_STAGE2=-fuse-ld=gold"
   ] ++ lib.optionals (disableLargeAddressSpace) [
     "--disable-large-address-space"
+  ] ++ lib.optionals enableUnregisterised [
+    "--enable-unregisterised"
   ];
 
   # Make sure we never relax`$PATH` and hooks support for compatibility.
@@ -358,6 +379,14 @@ stdenv.mkDerivation (rec {
   requiredSystemFeatures = [ "big-parallel" ];
 
   postInstall = ''
+    # Make the installed GHC use the host platform's tools.
+    sed -i $out/lib/${targetPrefix}${passthru.haskellCompilerName}/settings \
+      -e "s!$CC!${installCC}/bin/${installCC.targetPrefix}cc!g" \
+      -e "s!$CXX!${installCC}/bin/${installCC.targetPrefix}c++!g" \
+      -e "s!$LD!${installCC.bintools}/bin/${installCC.bintools.targetPrefix}ld${lib.optionalString useLdGold ".gold"}!g" \
+      -e "s!$AR!${installCC.bintools.bintools}/bin/${installCC.bintools.targetPrefix}ar!g" \
+      -e "s!$RANLIB!${installCC.bintools.bintools}/bin/${installCC.bintools.targetPrefix}ranlib!g"
+
     # Install the bash completion file.
     install -D -m 444 utils/completion/ghc.bash $out/share/bash-completion/completions/${targetPrefix}ghc
   '';
@@ -383,7 +412,8 @@ stdenv.mkDerivation (rec {
       guibou
     ] ++ lib.teams.haskell.members;
     timeout = 24 * 3600;
-    inherit (ghc.meta) license platforms;
+    platforms = lib.platforms.all;
+    inherit (ghc.meta) license;
   };
 
 } // lib.optionalAttrs targetPlatform.useAndroidPrebuilt {
diff --git a/pkgs/development/compilers/ghc/9.2.5.nix b/pkgs/development/compilers/ghc/9.2.5.nix
index 6c86e05ebbd4c..36ede2a27aa7c 100644
--- a/pkgs/development/compilers/ghc/9.2.5.nix
+++ b/pkgs/development/compilers/ghc/9.2.5.nix
@@ -1,4 +1,4 @@
-{ lib, stdenv, pkgsBuildTarget, pkgsHostTarget, targetPackages
+{ lib, stdenv, pkgsBuildTarget, pkgsHostTarget, buildPackages, targetPackages
 
 # build-tools
 , bootPkgs
@@ -46,25 +46,37 @@
 
 , #  Whether to build sphinx documentation.
   enableDocs ? (
-    # Docs disabled if we are building on musl because it's a large task to keep
-    # all `sphinx` dependencies building in this environment.
-    !stdenv.buildPlatform.isMusl
+    # Docs disabled if we are building on musl or cross-building because it's a
+    # large task to keep all `sphinx` dependencies building in this environment.
+    (stdenv.buildPlatform == stdenv.hostPlatform && stdenv.targetPlatform == stdenv.hostPlatform)
+    && !stdenv.buildPlatform.isMusl
   )
 
 , enableHaddockProgram ?
     # Disabled for cross; see note [HADDOCK_DOCS].
-    (stdenv.targetPlatform == stdenv.hostPlatform)
+    (stdenv.buildPlatform == stdenv.hostPlatform && 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
+
+, # Whether to build an unregisterised version of GHC.
+  # GHC will normally auto-detect whether it can do a registered build, but this
+  # option will force it to do an unregistered build when set to true.
+  # See https://gitlab.haskell.org/ghc/ghc/-/wikis/building/unregisterised
+  # Registerised RV64 compiler produces programs that segfault
+  # See https://gitlab.haskell.org/ghc/ghc/-/issues/23957
+  enableUnregisterised ? stdenv.hostPlatform.isRiscV64 || stdenv.targetPlatform.isRiscV64
 }:
 
 assert !enableNativeBignum -> gmp != null;
 
 # Cross cannot currently build the `haddock` program for silly reasons,
 # see note [HADDOCK_DOCS].
-assert (stdenv.targetPlatform != stdenv.hostPlatform) -> !enableHaddockProgram;
+assert (stdenv.buildPlatform != stdenv.hostPlatform || stdenv.targetPlatform != stdenv.hostPlatform) -> !enableHaddockProgram;
+
+# GHC does not support building when all 3 platforms are different.
+assert stdenv.buildPlatform == stdenv.hostPlatform || stdenv.hostPlatform == stdenv.targetPlatform;
 
 let
   inherit (stdenv) buildPlatform hostPlatform targetPlatform;
@@ -129,7 +141,9 @@ let
     pkgsBuildTarget.targetPackages.stdenv.cc
   ] ++ lib.optional useLLVM buildTargetLlvmPackages.llvm;
 
+  buildCC = buildPackages.stdenv.cc;
   targetCC = builtins.head toolsForTarget;
+  installCC = pkgsHostTarget.targetPackages.stdenv.cc;
 
   # Sometimes we have to dispatch between the bintools wrapper and the unwrapped
   # derivation for certain tools depending on the platform.
@@ -161,14 +175,11 @@ let
     (lib.optionalString enableNativeBignum "-native-bignum")
   ];
 
-in
+  targetLibffi = if hostPlatform != targetPlatform
+    then targetPackages.libffi
+    else pkgsHostTarget.libffi;
 
-# 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;
+in
 
 stdenv.mkDerivation (rec {
   version = "9.2.5";
@@ -223,6 +234,9 @@ stdenv.mkDerivation (rec {
   # GHC needs the locale configured during the Haddock phase.
   LANG = "en_US.UTF-8";
 
+  # GHC is unable to build a cross-compiler without this set.
+  "NIX_CC_WRAPPER_TARGET_HOST_${buildCC.suffixSalt}" = 1;
+
   # GHC is a bit confused on its cross terminology.
   # TODO(@sternenseemann): investigate coreutils dependencies and pass absolute paths
   preConfigure = ''
@@ -251,6 +265,10 @@ stdenv.mkDerivation (rec {
     # LLVM backend on Darwin needs clang: https://downloads.haskell.org/~ghc/latest/docs/html/users_guide/codegens.html#llvm-code-generator-fllvm
     export CLANG="${buildTargetLlvmPackages.clang}/bin/${buildTargetLlvmPackages.clang.targetPrefix}clang"
   '' + ''
+    export CC_STAGE0="${buildCC}/bin/${buildCC.targetPrefix}cc"
+    export LD_STAGE0="${buildCC.bintools}/bin/${buildCC.bintools.targetPrefix}ld"
+    export AR_STAGE0="${buildCC.bintools.bintools}/bin/${buildCC.bintools.targetPrefix}ar"
+
     echo -n "${buildMK}" > mk/build.mk
   '' + lib.optionalString (stdenv.isLinux && hostPlatform.libc == "glibc") ''
     export LOCALE_ARCHIVE="${glibcLocales}/lib/locale/locale-archive"
@@ -281,18 +299,22 @@ stdenv.mkDerivation (rec {
       done
   '';
 
+  # Although it is usually correct to pass --host, we don't do that here because
+  # GHC's usage of build, host, and target is non-standard.
+  # See https://gitlab.haskell.org/ghc/ghc/-/wikis/building/cross-compiling
   # TODO(@Ericson2314): Always pass "--target" and always prefix.
-  configurePlatforms = [ "build" "host" ]
-    ++ lib.optional (targetPlatform != hostPlatform) "target";
+  configurePlatforms = [ "build" ]
+    ++ lib.optional (buildPlatform != hostPlatform || 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=${ncurses.out}/lib"
+    "--with-curses-includes=${buildPackages.ncurses.dev}/include"
+    "--with-curses-libraries=${buildPackages.ncurses.out}/lib"
   ] ++ lib.optionals (libffi != null) [
     "--with-system-libffi"
-    "--with-ffi-includes=${targetPackages.libffi.dev}/include"
-    "--with-ffi-libraries=${targetPackages.libffi.out}/lib"
+    "--with-ffi-includes=${targetLibffi.dev}/include"
+    "--with-ffi-libraries=${targetLibffi.out}/lib"
   ] ++ lib.optionals (targetPlatform == hostPlatform && !enableNativeBignum) [
     "--with-gmp-includes=${targetPackages.gmp.dev}/include"
     "--with-gmp-libraries=${targetPackages.gmp.out}/lib"
@@ -307,6 +329,8 @@ stdenv.mkDerivation (rec {
     "CONF_GCC_LINKER_OPTS_STAGE2=-fuse-ld=gold"
   ] ++ lib.optionals (disableLargeAddressSpace) [
     "--disable-large-address-space"
+  ] ++ lib.optionals enableUnregisterised [
+    "--enable-unregisterised"
   ];
 
   # Make sure we never relax`$PATH` and hooks support for compatibility.
@@ -354,6 +378,14 @@ stdenv.mkDerivation (rec {
   requiredSystemFeatures = [ "big-parallel" ];
 
   postInstall = ''
+    # Make the installed GHC use the host platform's tools.
+    sed -i $out/lib/${targetPrefix}${passthru.haskellCompilerName}/settings \
+      -e "s!$CC!${installCC}/bin/${installCC.targetPrefix}cc!g" \
+      -e "s!$CXX!${installCC}/bin/${installCC.targetPrefix}c++!g" \
+      -e "s!$LD!${installCC.bintools}/bin/${installCC.bintools.targetPrefix}ld${lib.optionalString useLdGold ".gold"}!g" \
+      -e "s!$AR!${installCC.bintools.bintools}/bin/${installCC.bintools.targetPrefix}ar!g" \
+      -e "s!$RANLIB!${installCC.bintools.bintools}/bin/${installCC.bintools.targetPrefix}ranlib!g"
+
     # Install the bash completion file.
     install -D -m 444 utils/completion/ghc.bash $out/share/bash-completion/completions/${targetPrefix}ghc
   '';
@@ -379,7 +411,8 @@ stdenv.mkDerivation (rec {
       guibou
     ] ++ lib.teams.haskell.members;
     timeout = 24 * 3600;
-    inherit (ghc.meta) license platforms;
+    platforms = lib.platforms.all;
+    inherit (ghc.meta) license;
   };
 
 } // lib.optionalAttrs targetPlatform.useAndroidPrebuilt {
diff --git a/pkgs/development/compilers/ghc/9.2.6.nix b/pkgs/development/compilers/ghc/9.2.6.nix
index 6ff58f087f8a9..af3a231baf4ab 100644
--- a/pkgs/development/compilers/ghc/9.2.6.nix
+++ b/pkgs/development/compilers/ghc/9.2.6.nix
@@ -1,4 +1,4 @@
-{ lib, stdenv, pkgsBuildTarget, pkgsHostTarget, targetPackages
+{ lib, stdenv, pkgsBuildTarget, pkgsHostTarget, buildPackages, targetPackages
 
 # build-tools
 , bootPkgs
@@ -46,25 +46,37 @@
 
 , #  Whether to build sphinx documentation.
   enableDocs ? (
-    # Docs disabled if we are building on musl because it's a large task to keep
-    # all `sphinx` dependencies building in this environment.
-    !stdenv.buildPlatform.isMusl
+    # Docs disabled if we are building on musl or cross-building because it's a
+    # large task to keep all `sphinx` dependencies building in this environment.
+    (stdenv.buildPlatform == stdenv.hostPlatform && stdenv.targetPlatform == stdenv.hostPlatform)
+    && !stdenv.buildPlatform.isMusl
   )
 
 , enableHaddockProgram ?
     # Disabled for cross; see note [HADDOCK_DOCS].
-    (stdenv.targetPlatform == stdenv.hostPlatform)
+    (stdenv.buildPlatform == stdenv.hostPlatform && 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
+
+, # Whether to build an unregisterised version of GHC.
+  # GHC will normally auto-detect whether it can do a registered build, but this
+  # option will force it to do an unregistered build when set to true.
+  # See https://gitlab.haskell.org/ghc/ghc/-/wikis/building/unregisterised
+  # Registerised RV64 compiler produces programs that segfault
+  # See https://gitlab.haskell.org/ghc/ghc/-/issues/23957
+  enableUnregisterised ? stdenv.hostPlatform.isRiscV64 || stdenv.targetPlatform.isRiscV64
 }:
 
 assert !enableNativeBignum -> gmp != null;
 
 # Cross cannot currently build the `haddock` program for silly reasons,
 # see note [HADDOCK_DOCS].
-assert (stdenv.targetPlatform != stdenv.hostPlatform) -> !enableHaddockProgram;
+assert (stdenv.buildPlatform != stdenv.hostPlatform || stdenv.targetPlatform != stdenv.hostPlatform) -> !enableHaddockProgram;
+
+# GHC does not support building when all 3 platforms are different.
+assert stdenv.buildPlatform == stdenv.hostPlatform || stdenv.hostPlatform == stdenv.targetPlatform;
 
 let
   inherit (stdenv) buildPlatform hostPlatform targetPlatform;
@@ -129,7 +141,9 @@ let
     pkgsBuildTarget.targetPackages.stdenv.cc
   ] ++ lib.optional useLLVM buildTargetLlvmPackages.llvm;
 
+  buildCC = buildPackages.stdenv.cc;
   targetCC = builtins.head toolsForTarget;
+  installCC = pkgsHostTarget.targetPackages.stdenv.cc;
 
   # Sometimes we have to dispatch between the bintools wrapper and the unwrapped
   # derivation for certain tools depending on the platform.
@@ -161,14 +175,11 @@ let
     (lib.optionalString enableNativeBignum "-native-bignum")
   ];
 
-in
+  targetLibffi = if hostPlatform != targetPlatform
+    then targetPackages.libffi
+    else pkgsHostTarget.libffi;
 
-# 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;
+in
 
 stdenv.mkDerivation (rec {
   version = "9.2.6";
@@ -223,6 +234,9 @@ stdenv.mkDerivation (rec {
   # GHC needs the locale configured during the Haddock phase.
   LANG = "en_US.UTF-8";
 
+  # GHC is unable to build a cross-compiler without this set.
+  "NIX_CC_WRAPPER_TARGET_HOST_${buildCC.suffixSalt}" = 1;
+
   # GHC is a bit confused on its cross terminology.
   # TODO(@sternenseemann): investigate coreutils dependencies and pass absolute paths
   preConfigure = ''
@@ -251,6 +265,10 @@ stdenv.mkDerivation (rec {
     # LLVM backend on Darwin needs clang: https://downloads.haskell.org/~ghc/latest/docs/html/users_guide/codegens.html#llvm-code-generator-fllvm
     export CLANG="${buildTargetLlvmPackages.clang}/bin/${buildTargetLlvmPackages.clang.targetPrefix}clang"
   '' + ''
+    export CC_STAGE0="${buildCC}/bin/${buildCC.targetPrefix}cc"
+    export LD_STAGE0="${buildCC.bintools}/bin/${buildCC.bintools.targetPrefix}ld"
+    export AR_STAGE0="${buildCC.bintools.bintools}/bin/${buildCC.bintools.targetPrefix}ar"
+
     echo -n "${buildMK}" > mk/build.mk
   '' + lib.optionalString (stdenv.isLinux && hostPlatform.libc == "glibc") ''
     export LOCALE_ARCHIVE="${glibcLocales}/lib/locale/locale-archive"
@@ -281,18 +299,22 @@ stdenv.mkDerivation (rec {
       done
   '';
 
+  # Although it is usually correct to pass --host, we don't do that here because
+  # GHC's usage of build, host, and target is non-standard.
+  # See https://gitlab.haskell.org/ghc/ghc/-/wikis/building/cross-compiling
   # TODO(@Ericson2314): Always pass "--target" and always prefix.
-  configurePlatforms = [ "build" "host" ]
-    ++ lib.optional (targetPlatform != hostPlatform) "target";
+  configurePlatforms = [ "build" ]
+    ++ lib.optional (buildPlatform != hostPlatform || 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=${ncurses.out}/lib"
+    "--with-curses-includes=${buildPackages.ncurses.dev}/include"
+    "--with-curses-libraries=${buildPackages.ncurses.out}/lib"
   ] ++ lib.optionals (libffi != null) [
     "--with-system-libffi"
-    "--with-ffi-includes=${targetPackages.libffi.dev}/include"
-    "--with-ffi-libraries=${targetPackages.libffi.out}/lib"
+    "--with-ffi-includes=${targetLibffi.dev}/include"
+    "--with-ffi-libraries=${targetLibffi.out}/lib"
   ] ++ lib.optionals (targetPlatform == hostPlatform && !enableNativeBignum) [
     "--with-gmp-includes=${targetPackages.gmp.dev}/include"
     "--with-gmp-libraries=${targetPackages.gmp.out}/lib"
@@ -307,6 +329,8 @@ stdenv.mkDerivation (rec {
     "CONF_GCC_LINKER_OPTS_STAGE2=-fuse-ld=gold"
   ] ++ lib.optionals (disableLargeAddressSpace) [
     "--disable-large-address-space"
+  ] ++ lib.optionals enableUnregisterised [
+    "--enable-unregisterised"
   ];
 
   # Make sure we never relax`$PATH` and hooks support for compatibility.
@@ -354,6 +378,14 @@ stdenv.mkDerivation (rec {
   requiredSystemFeatures = [ "big-parallel" ];
 
   postInstall = ''
+    # Make the installed GHC use the host platform's tools.
+    sed -i $out/lib/${targetPrefix}${passthru.haskellCompilerName}/settings \
+      -e "s!$CC!${installCC}/bin/${installCC.targetPrefix}cc!g" \
+      -e "s!$CXX!${installCC}/bin/${installCC.targetPrefix}c++!g" \
+      -e "s!$LD!${installCC.bintools}/bin/${installCC.bintools.targetPrefix}ld${lib.optionalString useLdGold ".gold"}!g" \
+      -e "s!$AR!${installCC.bintools.bintools}/bin/${installCC.bintools.targetPrefix}ar!g" \
+      -e "s!$RANLIB!${installCC.bintools.bintools}/bin/${installCC.bintools.targetPrefix}ranlib!g"
+
     # Install the bash completion file.
     install -D -m 444 utils/completion/ghc.bash $out/share/bash-completion/completions/${targetPrefix}ghc
   '';
@@ -379,7 +411,8 @@ stdenv.mkDerivation (rec {
       guibou
     ] ++ lib.teams.haskell.members;
     timeout = 24 * 3600;
-    inherit (ghc.meta) license platforms;
+    platforms = lib.platforms.all;
+    inherit (ghc.meta) license;
   };
 
 } // lib.optionalAttrs targetPlatform.useAndroidPrebuilt {
diff --git a/pkgs/development/compilers/ghc/9.2.7.nix b/pkgs/development/compilers/ghc/9.2.7.nix
index f605bfda1981f..a9f8cc4bf680d 100644
--- a/pkgs/development/compilers/ghc/9.2.7.nix
+++ b/pkgs/development/compilers/ghc/9.2.7.nix
@@ -1,4 +1,4 @@
-{ lib, stdenv, pkgsBuildTarget, pkgsHostTarget, targetPackages
+{ lib, stdenv, pkgsBuildTarget, pkgsHostTarget, buildPackages, targetPackages
 
 # build-tools
 , bootPkgs
@@ -46,25 +46,37 @@
 
 , #  Whether to build sphinx documentation.
   enableDocs ? (
-    # Docs disabled if we are building on musl because it's a large task to keep
-    # all `sphinx` dependencies building in this environment.
-    !stdenv.buildPlatform.isMusl
+    # Docs disabled if we are building on musl or cross-building because it's a
+    # large task to keep all `sphinx` dependencies building in this environment.
+    (stdenv.buildPlatform == stdenv.hostPlatform && stdenv.targetPlatform == stdenv.hostPlatform)
+    && !stdenv.buildPlatform.isMusl
   )
 
 , enableHaddockProgram ?
     # Disabled for cross; see note [HADDOCK_DOCS].
-    (stdenv.targetPlatform == stdenv.hostPlatform)
+    (stdenv.buildPlatform == stdenv.hostPlatform && 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
+
+, # Whether to build an unregisterised version of GHC.
+  # GHC will normally auto-detect whether it can do a registered build, but this
+  # option will force it to do an unregistered build when set to true.
+  # See https://gitlab.haskell.org/ghc/ghc/-/wikis/building/unregisterised
+  # Registerised RV64 compiler produces programs that segfault
+  # See https://gitlab.haskell.org/ghc/ghc/-/issues/23957
+  enableUnregisterised ? stdenv.hostPlatform.isRiscV64 || stdenv.targetPlatform.isRiscV64
 }:
 
 assert !enableNativeBignum -> gmp != null;
 
 # Cross cannot currently build the `haddock` program for silly reasons,
 # see note [HADDOCK_DOCS].
-assert (stdenv.targetPlatform != stdenv.hostPlatform) -> !enableHaddockProgram;
+assert (stdenv.buildPlatform != stdenv.hostPlatform || stdenv.targetPlatform != stdenv.hostPlatform) -> !enableHaddockProgram;
+
+# GHC does not support building when all 3 platforms are different.
+assert stdenv.buildPlatform == stdenv.hostPlatform || stdenv.hostPlatform == stdenv.targetPlatform;
 
 let
   inherit (stdenv) buildPlatform hostPlatform targetPlatform;
@@ -129,7 +141,9 @@ let
     pkgsBuildTarget.targetPackages.stdenv.cc
   ] ++ lib.optional useLLVM buildTargetLlvmPackages.llvm;
 
+  buildCC = buildPackages.stdenv.cc;
   targetCC = builtins.head toolsForTarget;
+  installCC = pkgsHostTarget.targetPackages.stdenv.cc;
 
   # Sometimes we have to dispatch between the bintools wrapper and the unwrapped
   # derivation for certain tools depending on the platform.
@@ -161,14 +175,11 @@ let
     (lib.optionalString enableNativeBignum "-native-bignum")
   ];
 
-in
+  targetLibffi = if hostPlatform != targetPlatform
+    then targetPackages.libffi
+    else pkgsHostTarget.libffi;
 
-# 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;
+in
 
 stdenv.mkDerivation (rec {
   version = "9.2.7";
@@ -223,6 +234,9 @@ stdenv.mkDerivation (rec {
   # GHC needs the locale configured during the Haddock phase.
   LANG = "en_US.UTF-8";
 
+  # GHC is unable to build a cross-compiler without this set.
+  "NIX_CC_WRAPPER_TARGET_HOST_${buildCC.suffixSalt}" = 1;
+
   # GHC is a bit confused on its cross terminology.
   # TODO(@sternenseemann): investigate coreutils dependencies and pass absolute paths
   preConfigure = ''
@@ -251,6 +265,10 @@ stdenv.mkDerivation (rec {
     # LLVM backend on Darwin needs clang: https://downloads.haskell.org/~ghc/latest/docs/html/users_guide/codegens.html#llvm-code-generator-fllvm
     export CLANG="${buildTargetLlvmPackages.clang}/bin/${buildTargetLlvmPackages.clang.targetPrefix}clang"
   '' + ''
+    export CC_STAGE0="${buildCC}/bin/${buildCC.targetPrefix}cc"
+    export LD_STAGE0="${buildCC.bintools}/bin/${buildCC.bintools.targetPrefix}ld"
+    export AR_STAGE0="${buildCC.bintools.bintools}/bin/${buildCC.bintools.targetPrefix}ar"
+
     echo -n "${buildMK}" > mk/build.mk
   '' + lib.optionalString (stdenv.isLinux && hostPlatform.libc == "glibc") ''
     export LOCALE_ARCHIVE="${glibcLocales}/lib/locale/locale-archive"
@@ -281,18 +299,22 @@ stdenv.mkDerivation (rec {
       done
   '';
 
+  # Although it is usually correct to pass --host, we don't do that here because
+  # GHC's usage of build, host, and target is non-standard.
+  # See https://gitlab.haskell.org/ghc/ghc/-/wikis/building/cross-compiling
   # TODO(@Ericson2314): Always pass "--target" and always prefix.
-  configurePlatforms = [ "build" "host" ]
-    ++ lib.optional (targetPlatform != hostPlatform) "target";
+  configurePlatforms = [ "build" ]
+    ++ lib.optional (buildPlatform != hostPlatform || 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=${ncurses.out}/lib"
+    "--with-curses-includes=${buildPackages.ncurses.dev}/include"
+    "--with-curses-libraries=${buildPackages.ncurses.out}/lib"
   ] ++ lib.optionals (libffi != null) [
     "--with-system-libffi"
-    "--with-ffi-includes=${targetPackages.libffi.dev}/include"
-    "--with-ffi-libraries=${targetPackages.libffi.out}/lib"
+    "--with-ffi-includes=${targetLibffi.dev}/include"
+    "--with-ffi-libraries=${targetLibffi.out}/lib"
   ] ++ lib.optionals (targetPlatform == hostPlatform && !enableNativeBignum) [
     "--with-gmp-includes=${targetPackages.gmp.dev}/include"
     "--with-gmp-libraries=${targetPackages.gmp.out}/lib"
@@ -307,6 +329,8 @@ stdenv.mkDerivation (rec {
     "CONF_GCC_LINKER_OPTS_STAGE2=-fuse-ld=gold"
   ] ++ lib.optionals (disableLargeAddressSpace) [
     "--disable-large-address-space"
+  ] ++ lib.optionals enableUnregisterised [
+    "--enable-unregisterised"
   ];
 
   # Make sure we never relax`$PATH` and hooks support for compatibility.
@@ -354,6 +378,14 @@ stdenv.mkDerivation (rec {
   requiredSystemFeatures = [ "big-parallel" ];
 
   postInstall = ''
+    # Make the installed GHC use the host platform's tools.
+    sed -i $out/lib/${targetPrefix}${passthru.haskellCompilerName}/settings \
+      -e "s!$CC!${installCC}/bin/${installCC.targetPrefix}cc!g" \
+      -e "s!$CXX!${installCC}/bin/${installCC.targetPrefix}c++!g" \
+      -e "s!$LD!${installCC.bintools}/bin/${installCC.bintools.targetPrefix}ld${lib.optionalString useLdGold ".gold"}!g" \
+      -e "s!$AR!${installCC.bintools.bintools}/bin/${installCC.bintools.targetPrefix}ar!g" \
+      -e "s!$RANLIB!${installCC.bintools.bintools}/bin/${installCC.bintools.targetPrefix}ranlib!g"
+
     # Install the bash completion file.
     install -D -m 444 utils/completion/ghc.bash $out/share/bash-completion/completions/${targetPrefix}ghc
   '';
@@ -379,7 +411,8 @@ stdenv.mkDerivation (rec {
       guibou
     ] ++ lib.teams.haskell.members;
     timeout = 24 * 3600;
-    inherit (ghc.meta) license platforms;
+    platforms = lib.platforms.all;
+    inherit (ghc.meta) license;
   };
 
 } // lib.optionalAttrs targetPlatform.useAndroidPrebuilt {
diff --git a/pkgs/development/compilers/ghc/9.2.8.nix b/pkgs/development/compilers/ghc/9.2.8.nix
index 72cfdd242f424..c8ca7f5c1d603 100644
--- a/pkgs/development/compilers/ghc/9.2.8.nix
+++ b/pkgs/development/compilers/ghc/9.2.8.nix
@@ -1,4 +1,4 @@
-{ lib, stdenv, pkgsBuildTarget, pkgsHostTarget, targetPackages
+{ lib, stdenv, pkgsBuildTarget, pkgsHostTarget, buildPackages, targetPackages
 
 # build-tools
 , bootPkgs
@@ -46,25 +46,37 @@
 
 , #  Whether to build sphinx documentation.
   enableDocs ? (
-    # Docs disabled if we are building on musl because it's a large task to keep
-    # all `sphinx` dependencies building in this environment.
-    !stdenv.buildPlatform.isMusl
+    # Docs disabled if we are building on musl or cross-building because it's a
+    # large task to keep all `sphinx` dependencies building in this environment.
+    (stdenv.buildPlatform == stdenv.hostPlatform && stdenv.targetPlatform == stdenv.hostPlatform)
+    && !stdenv.buildPlatform.isMusl
   )
 
 , enableHaddockProgram ?
     # Disabled for cross; see note [HADDOCK_DOCS].
-    (stdenv.targetPlatform == stdenv.hostPlatform)
+    (stdenv.buildPlatform == stdenv.hostPlatform && 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
+
+, # Whether to build an unregisterised version of GHC.
+  # GHC will normally auto-detect whether it can do a registered build, but this
+  # option will force it to do an unregistered build when set to true.
+  # See https://gitlab.haskell.org/ghc/ghc/-/wikis/building/unregisterised
+  # Registerised RV64 compiler produces programs that segfault
+  # See https://gitlab.haskell.org/ghc/ghc/-/issues/23957
+  enableUnregisterised ? stdenv.hostPlatform.isRiscV64 || stdenv.targetPlatform.isRiscV64
 }:
 
 assert !enableNativeBignum -> gmp != null;
 
 # Cross cannot currently build the `haddock` program for silly reasons,
 # see note [HADDOCK_DOCS].
-assert (stdenv.targetPlatform != stdenv.hostPlatform) -> !enableHaddockProgram;
+assert (stdenv.buildPlatform != stdenv.hostPlatform || stdenv.targetPlatform != stdenv.hostPlatform) -> !enableHaddockProgram;
+
+# GHC does not support building when all 3 platforms are different.
+assert stdenv.buildPlatform == stdenv.hostPlatform || stdenv.hostPlatform == stdenv.targetPlatform;
 
 let
   inherit (stdenv) buildPlatform hostPlatform targetPlatform;
@@ -129,7 +141,9 @@ let
     pkgsBuildTarget.targetPackages.stdenv.cc
   ] ++ lib.optional useLLVM buildTargetLlvmPackages.llvm;
 
+  buildCC = buildPackages.stdenv.cc;
   targetCC = builtins.head toolsForTarget;
+  installCC = pkgsHostTarget.targetPackages.stdenv.cc;
 
   # Sometimes we have to dispatch between the bintools wrapper and the unwrapped
   # derivation for certain tools depending on the platform.
@@ -161,14 +175,11 @@ let
     (lib.optionalString enableNativeBignum "-native-bignum")
   ];
 
-in
+  targetLibffi = if hostPlatform != targetPlatform
+    then targetPackages.libffi
+    else pkgsHostTarget.libffi;
 
-# 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;
+in
 
 stdenv.mkDerivation (rec {
   version = "9.2.8";
@@ -223,6 +234,9 @@ stdenv.mkDerivation (rec {
   # GHC needs the locale configured during the Haddock phase.
   LANG = "en_US.UTF-8";
 
+  # GHC is unable to build a cross-compiler without this set.
+  "NIX_CC_WRAPPER_TARGET_HOST_${buildCC.suffixSalt}" = 1;
+
   # GHC is a bit confused on its cross terminology.
   # TODO(@sternenseemann): investigate coreutils dependencies and pass absolute paths
   preConfigure = ''
@@ -251,6 +265,10 @@ stdenv.mkDerivation (rec {
     # LLVM backend on Darwin needs clang: https://downloads.haskell.org/~ghc/latest/docs/html/users_guide/codegens.html#llvm-code-generator-fllvm
     export CLANG="${buildTargetLlvmPackages.clang}/bin/${buildTargetLlvmPackages.clang.targetPrefix}clang"
   '' + ''
+    export CC_STAGE0="${buildCC}/bin/${buildCC.targetPrefix}cc"
+    export LD_STAGE0="${buildCC.bintools}/bin/${buildCC.bintools.targetPrefix}ld"
+    export AR_STAGE0="${buildCC.bintools.bintools}/bin/${buildCC.bintools.targetPrefix}ar"
+
     echo -n "${buildMK}" > mk/build.mk
   '' + lib.optionalString (stdenv.isLinux && hostPlatform.libc == "glibc") ''
     export LOCALE_ARCHIVE="${glibcLocales}/lib/locale/locale-archive"
@@ -281,18 +299,22 @@ stdenv.mkDerivation (rec {
       done
   '';
 
+  # Although it is usually correct to pass --host, we don't do that here because
+  # GHC's usage of build, host, and target is non-standard.
+  # See https://gitlab.haskell.org/ghc/ghc/-/wikis/building/cross-compiling
   # TODO(@Ericson2314): Always pass "--target" and always prefix.
-  configurePlatforms = [ "build" "host" ]
-    ++ lib.optional (targetPlatform != hostPlatform) "target";
+  configurePlatforms = [ "build" ]
+    ++ lib.optional (buildPlatform != hostPlatform || 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=${ncurses.out}/lib"
+    "--with-curses-includes=${buildPackages.ncurses.dev}/include"
+    "--with-curses-libraries=${buildPackages.ncurses.out}/lib"
   ] ++ lib.optionals (libffi != null) [
     "--with-system-libffi"
-    "--with-ffi-includes=${targetPackages.libffi.dev}/include"
-    "--with-ffi-libraries=${targetPackages.libffi.out}/lib"
+    "--with-ffi-includes=${targetLibffi.dev}/include"
+    "--with-ffi-libraries=${targetLibffi.out}/lib"
   ] ++ lib.optionals (targetPlatform == hostPlatform && !enableNativeBignum) [
     "--with-gmp-includes=${targetPackages.gmp.dev}/include"
     "--with-gmp-libraries=${targetPackages.gmp.out}/lib"
@@ -307,6 +329,8 @@ stdenv.mkDerivation (rec {
     "CONF_GCC_LINKER_OPTS_STAGE2=-fuse-ld=gold"
   ] ++ lib.optionals (disableLargeAddressSpace) [
     "--disable-large-address-space"
+  ] ++ lib.optionals enableUnregisterised [
+    "--enable-unregisterised"
   ];
 
   # Make sure we never relax`$PATH` and hooks support for compatibility.
@@ -354,6 +378,14 @@ stdenv.mkDerivation (rec {
   requiredSystemFeatures = [ "big-parallel" ];
 
   postInstall = ''
+    # Make the installed GHC use the host platform's tools.
+    sed -i $out/lib/${targetPrefix}${passthru.haskellCompilerName}/settings \
+      -e "s!$CC!${installCC}/bin/${installCC.targetPrefix}cc!g" \
+      -e "s!$CXX!${installCC}/bin/${installCC.targetPrefix}c++!g" \
+      -e "s!$LD!${installCC.bintools}/bin/${installCC.bintools.targetPrefix}ld${lib.optionalString useLdGold ".gold"}!g" \
+      -e "s!$AR!${installCC.bintools.bintools}/bin/${installCC.bintools.targetPrefix}ar!g" \
+      -e "s!$RANLIB!${installCC.bintools.bintools}/bin/${installCC.bintools.targetPrefix}ranlib!g"
+
     # Install the bash completion file.
     install -D -m 444 utils/completion/ghc.bash $out/share/bash-completion/completions/${targetPrefix}ghc
   '';
@@ -379,7 +411,8 @@ stdenv.mkDerivation (rec {
       guibou
     ] ++ lib.teams.haskell.members;
     timeout = 24 * 3600;
-    inherit (ghc.meta) license platforms;
+    platforms = lib.platforms.all;
+    inherit (ghc.meta) license;
   };
 
 } // lib.optionalAttrs targetPlatform.useAndroidPrebuilt {
diff --git a/pkgs/development/compilers/ghc/9.4.5.nix b/pkgs/development/compilers/ghc/9.4.5.nix
index 298af6596e713..3060a91a85c91 100644
--- a/pkgs/development/compilers/ghc/9.4.5.nix
+++ b/pkgs/development/compilers/ghc/9.4.5.nix
@@ -1,6 +1,6 @@
 # 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
+{ lib, stdenv, pkgsBuildTarget, pkgsHostTarget, buildPackages, targetPackages
 
 # build-tools
 , bootPkgs
@@ -48,25 +48,37 @@
 
 , #  Whether to build sphinx documentation.
   enableDocs ? (
-    # Docs disabled if we are building on musl because it's a large task to keep
-    # all `sphinx` dependencies building in this environment.
-    !stdenv.buildPlatform.isMusl
+    # Docs disabled if we are building on musl or cross-building because it's a
+    # large task to keep all `sphinx` dependencies building in this environment.
+    (stdenv.buildPlatform == stdenv.hostPlatform && stdenv.targetPlatform == stdenv.hostPlatform)
+    && !stdenv.buildPlatform.isMusl
   )
 
 , enableHaddockProgram ?
     # Disabled for cross; see note [HADDOCK_DOCS].
-    (stdenv.targetPlatform == stdenv.hostPlatform)
+    (stdenv.buildPlatform == stdenv.hostPlatform && 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
+
+, # Whether to build an unregisterised version of GHC.
+  # GHC will normally auto-detect whether it can do a registered build, but this
+  # option will force it to do an unregistered build when set to true.
+  # See https://gitlab.haskell.org/ghc/ghc/-/wikis/building/unregisterised
+  # Registerised RV64 compiler produces programs that segfault
+  # See https://gitlab.haskell.org/ghc/ghc/-/issues/23957
+  enableUnregisterised ? stdenv.hostPlatform.isRiscV64 || stdenv.targetPlatform.isRiscV64
 }:
 
 assert !enableNativeBignum -> gmp != null;
 
 # Cross cannot currently build the `haddock` program for silly reasons,
 # see note [HADDOCK_DOCS].
-assert (stdenv.targetPlatform != stdenv.hostPlatform) -> !enableHaddockProgram;
+assert (stdenv.buildPlatform != stdenv.hostPlatform || stdenv.targetPlatform != stdenv.hostPlatform) -> !enableHaddockProgram;
+
+# GHC does not support building when all 3 platforms are different.
+assert stdenv.buildPlatform == stdenv.hostPlatform || stdenv.hostPlatform == stdenv.targetPlatform;
 
 let
   inherit (stdenv) buildPlatform hostPlatform targetPlatform;
@@ -131,7 +143,9 @@ let
     pkgsBuildTarget.targetPackages.stdenv.cc
   ] ++ lib.optional useLLVM buildTargetLlvmPackages.llvm;
 
+  buildCC = buildPackages.stdenv.cc;
   targetCC = builtins.head toolsForTarget;
+  installCC = pkgsHostTarget.targetPackages.stdenv.cc;
 
   # Sometimes we have to dispatch between the bintools wrapper and the unwrapped
   # derivation for certain tools depending on the platform.
@@ -163,14 +177,11 @@ let
     (lib.optionalString enableNativeBignum "-native-bignum")
   ];
 
-in
+  targetLibffi = if hostPlatform != targetPlatform
+    then targetPackages.libffi
+    else pkgsHostTarget.libffi;
 
-# 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;
+in
 
 stdenv.mkDerivation (rec {
   version = "9.4.5";
@@ -220,6 +231,9 @@ stdenv.mkDerivation (rec {
   # GHC needs the locale configured during the Haddock phase.
   LANG = "en_US.UTF-8";
 
+  # GHC is unable to build a cross-compiler without this set.
+  "NIX_CC_WRAPPER_TARGET_HOST_${buildCC.suffixSalt}" = 1;
+
   # GHC is a bit confused on its cross terminology.
   # TODO(@sternenseemann): investigate coreutils dependencies and pass absolute paths
   preConfigure = ''
@@ -248,6 +262,9 @@ stdenv.mkDerivation (rec {
     # LLVM backend on Darwin needs clang: https://downloads.haskell.org/~ghc/latest/docs/html/users_guide/codegens.html#llvm-code-generator-fllvm
     export CLANG="${buildTargetLlvmPackages.clang}/bin/${buildTargetLlvmPackages.clang.targetPrefix}clang"
   '' + ''
+    export CC_STAGE0="${buildCC}/bin/${buildCC.targetPrefix}cc"
+    export LD_STAGE0="${buildCC.bintools}/bin/${buildCC.bintools.targetPrefix}ld"
+    export AR_STAGE0="${buildCC.bintools.bintools}/bin/${buildCC.bintools.targetPrefix}ar"
 
     echo -n "${buildMK}" > mk/build.mk
 
@@ -288,18 +305,22 @@ stdenv.mkDerivation (rec {
       'MinBootGhcVersion="8.10"'
   '';
 
+  # Although it is usually correct to pass --host, we don't do that here because
+  # GHC's usage of build, host, and target is non-standard.
+  # See https://gitlab.haskell.org/ghc/ghc/-/wikis/building/cross-compiling
   # TODO(@Ericson2314): Always pass "--target" and always prefix.
-  configurePlatforms = [ "build" "host" ]
-    ++ lib.optional (targetPlatform != hostPlatform) "target";
+  configurePlatforms = [ "build" ]
+    ++ lib.optional (buildPlatform != hostPlatform || 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=${ncurses.out}/lib"
+    "--with-curses-includes=${buildPackages.ncurses.dev}/include"
+    "--with-curses-libraries=${buildPackages.ncurses.out}/lib"
   ] ++ lib.optionals (libffi != null) [
     "--with-system-libffi"
-    "--with-ffi-includes=${targetPackages.libffi.dev}/include"
-    "--with-ffi-libraries=${targetPackages.libffi.out}/lib"
+    "--with-ffi-includes=${targetLibffi.dev}/include"
+    "--with-ffi-libraries=${targetLibffi.out}/lib"
   ] ++ lib.optionals (targetPlatform == hostPlatform && !enableNativeBignum) [
     "--with-gmp-includes=${targetPackages.gmp.dev}/include"
     "--with-gmp-libraries=${targetPackages.gmp.out}/lib"
@@ -314,6 +335,8 @@ stdenv.mkDerivation (rec {
     "CONF_GCC_LINKER_OPTS_STAGE2=-fuse-ld=gold"
   ] ++ lib.optionals (disableLargeAddressSpace) [
     "--disable-large-address-space"
+  ] ++ lib.optionals enableUnregisterised [
+    "--enable-unregisterised"
   ];
 
   # Make sure we never relax`$PATH` and hooks support for compatibility.
@@ -361,6 +384,14 @@ stdenv.mkDerivation (rec {
   requiredSystemFeatures = [ "big-parallel" ];
 
   postInstall = ''
+    # Make the installed GHC use the host platform's tools.
+    sed -i $out/lib/${targetPrefix}${passthru.haskellCompilerName}/settings \
+      -e "s!$CC!${installCC}/bin/${installCC.targetPrefix}cc!g" \
+      -e "s!$CXX!${installCC}/bin/${installCC.targetPrefix}c++!g" \
+      -e "s!$LD!${installCC.bintools}/bin/${installCC.bintools.targetPrefix}ld${lib.optionalString useLdGold ".gold"}!g" \
+      -e "s!$AR!${installCC.bintools.bintools}/bin/${installCC.bintools.targetPrefix}ar!g" \
+      -e "s!$RANLIB!${installCC.bintools.bintools}/bin/${installCC.bintools.targetPrefix}ranlib!g"
+
     # Install the bash completion file.
     install -D -m 444 utils/completion/ghc.bash $out/share/bash-completion/completions/${targetPrefix}ghc
   '';
@@ -386,7 +417,8 @@ stdenv.mkDerivation (rec {
       guibou
     ] ++ lib.teams.haskell.members;
     timeout = 24 * 3600;
-    inherit (ghc.meta) license platforms;
+    platforms = lib.platforms.all;
+    inherit (ghc.meta) license;
   };
 
 } // lib.optionalAttrs targetPlatform.useAndroidPrebuilt {
diff --git a/pkgs/development/compilers/ghc/9.4.6.nix b/pkgs/development/compilers/ghc/9.4.6.nix
index 310787e477b24..82dcbbebf2141 100644
--- a/pkgs/development/compilers/ghc/9.4.6.nix
+++ b/pkgs/development/compilers/ghc/9.4.6.nix
@@ -1,6 +1,6 @@
 # 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
+{ lib, stdenv, pkgsBuildTarget, pkgsHostTarget, buildPackages, targetPackages
 
 # build-tools
 , bootPkgs
@@ -48,25 +48,37 @@
 
 , #  Whether to build sphinx documentation.
   enableDocs ? (
-    # Docs disabled if we are building on musl because it's a large task to keep
-    # all `sphinx` dependencies building in this environment.
-    !stdenv.buildPlatform.isMusl
+    # Docs disabled if we are building on musl or cross-building because it's a
+    # large task to keep all `sphinx` dependencies building in this environment.
+    (stdenv.buildPlatform == stdenv.hostPlatform && stdenv.targetPlatform == stdenv.hostPlatform)
+    && !stdenv.buildPlatform.isMusl
   )
 
 , enableHaddockProgram ?
     # Disabled for cross; see note [HADDOCK_DOCS].
-    (stdenv.targetPlatform == stdenv.hostPlatform)
+    (stdenv.buildPlatform == stdenv.hostPlatform && 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
+
+, # Whether to build an unregisterised version of GHC.
+  # GHC will normally auto-detect whether it can do a registered build, but this
+  # option will force it to do an unregistered build when set to true.
+  # See https://gitlab.haskell.org/ghc/ghc/-/wikis/building/unregisterised
+  # Registerised RV64 compiler produces programs that segfault
+  # See https://gitlab.haskell.org/ghc/ghc/-/issues/23957
+  enableUnregisterised ? stdenv.hostPlatform.isRiscV64 || stdenv.targetPlatform.isRiscV64
 }:
 
 assert !enableNativeBignum -> gmp != null;
 
 # Cross cannot currently build the `haddock` program for silly reasons,
 # see note [HADDOCK_DOCS].
-assert (stdenv.targetPlatform != stdenv.hostPlatform) -> !enableHaddockProgram;
+assert (stdenv.buildPlatform != stdenv.hostPlatform || stdenv.targetPlatform != stdenv.hostPlatform) -> !enableHaddockProgram;
+
+# GHC does not support building when all 3 platforms are different.
+assert stdenv.buildPlatform == stdenv.hostPlatform || stdenv.hostPlatform == stdenv.targetPlatform;
 
 let
   inherit (stdenv) buildPlatform hostPlatform targetPlatform;
@@ -131,7 +143,9 @@ let
     pkgsBuildTarget.targetPackages.stdenv.cc
   ] ++ lib.optional useLLVM buildTargetLlvmPackages.llvm;
 
+  buildCC = buildPackages.stdenv.cc;
   targetCC = builtins.head toolsForTarget;
+  installCC = pkgsHostTarget.targetPackages.stdenv.cc;
 
   # Sometimes we have to dispatch between the bintools wrapper and the unwrapped
   # derivation for certain tools depending on the platform.
@@ -163,14 +177,11 @@ let
     (lib.optionalString enableNativeBignum "-native-bignum")
   ];
 
-in
+  targetLibffi = if hostPlatform != targetPlatform
+    then targetPackages.libffi
+    else pkgsHostTarget.libffi;
 
-# 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;
+in
 
 stdenv.mkDerivation (rec {
   version = "9.4.6";
@@ -216,6 +227,9 @@ stdenv.mkDerivation (rec {
   # GHC needs the locale configured during the Haddock phase.
   LANG = "en_US.UTF-8";
 
+  # GHC is unable to build a cross-compiler without this set.
+  "NIX_CC_WRAPPER_TARGET_HOST_${buildCC.suffixSalt}" = 1;
+
   # GHC is a bit confused on its cross terminology.
   # TODO(@sternenseemann): investigate coreutils dependencies and pass absolute paths
   preConfigure = ''
@@ -244,6 +258,9 @@ stdenv.mkDerivation (rec {
     # LLVM backend on Darwin needs clang: https://downloads.haskell.org/~ghc/latest/docs/html/users_guide/codegens.html#llvm-code-generator-fllvm
     export CLANG="${buildTargetLlvmPackages.clang}/bin/${buildTargetLlvmPackages.clang.targetPrefix}clang"
   '' + ''
+    export CC_STAGE0="${buildCC}/bin/${buildCC.targetPrefix}cc"
+    export LD_STAGE0="${buildCC.bintools}/bin/${buildCC.bintools.targetPrefix}ld"
+    export AR_STAGE0="${buildCC.bintools.bintools}/bin/${buildCC.bintools.targetPrefix}ar"
 
     echo -n "${buildMK}" > mk/build.mk
 
@@ -284,18 +301,22 @@ stdenv.mkDerivation (rec {
       'MinBootGhcVersion="8.10"'
   '';
 
+  # Although it is usually correct to pass --host, we don't do that here because
+  # GHC's usage of build, host, and target is non-standard.
+  # See https://gitlab.haskell.org/ghc/ghc/-/wikis/building/cross-compiling
   # TODO(@Ericson2314): Always pass "--target" and always prefix.
-  configurePlatforms = [ "build" "host" ]
-    ++ lib.optional (targetPlatform != hostPlatform) "target";
+  configurePlatforms = [ "build" ]
+    ++ lib.optional (buildPlatform != hostPlatform || 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=${ncurses.out}/lib"
+    "--with-curses-includes=${buildPackages.ncurses.dev}/include"
+    "--with-curses-libraries=${buildPackages.ncurses.out}/lib"
   ] ++ lib.optionals (libffi != null) [
     "--with-system-libffi"
-    "--with-ffi-includes=${targetPackages.libffi.dev}/include"
-    "--with-ffi-libraries=${targetPackages.libffi.out}/lib"
+    "--with-ffi-includes=${targetLibffi.dev}/include"
+    "--with-ffi-libraries=${targetLibffi.out}/lib"
   ] ++ lib.optionals (targetPlatform == hostPlatform && !enableNativeBignum) [
     "--with-gmp-includes=${targetPackages.gmp.dev}/include"
     "--with-gmp-libraries=${targetPackages.gmp.out}/lib"
@@ -310,6 +331,8 @@ stdenv.mkDerivation (rec {
     "CONF_GCC_LINKER_OPTS_STAGE2=-fuse-ld=gold"
   ] ++ lib.optionals (disableLargeAddressSpace) [
     "--disable-large-address-space"
+  ] ++ lib.optionals enableUnregisterised [
+    "--enable-unregisterised"
   ];
 
   # Make sure we never relax`$PATH` and hooks support for compatibility.
@@ -357,6 +380,14 @@ stdenv.mkDerivation (rec {
   requiredSystemFeatures = [ "big-parallel" ];
 
   postInstall = ''
+    # Make the installed GHC use the host platform's tools.
+    sed -i $out/lib/${targetPrefix}${passthru.haskellCompilerName}/settings \
+      -e "s!$CC!${installCC}/bin/${installCC.targetPrefix}cc!g" \
+      -e "s!$CXX!${installCC}/bin/${installCC.targetPrefix}c++!g" \
+      -e "s!$LD!${installCC.bintools}/bin/${installCC.bintools.targetPrefix}ld${lib.optionalString useLdGold ".gold"}!g" \
+      -e "s!$AR!${installCC.bintools.bintools}/bin/${installCC.bintools.targetPrefix}ar!g" \
+      -e "s!$RANLIB!${installCC.bintools.bintools}/bin/${installCC.bintools.targetPrefix}ranlib!g"
+
     # Install the bash completion file.
     install -D -m 444 utils/completion/ghc.bash $out/share/bash-completion/completions/${targetPrefix}ghc
   '';
@@ -382,7 +413,8 @@ stdenv.mkDerivation (rec {
       guibou
     ] ++ lib.teams.haskell.members;
     timeout = 24 * 3600;
-    inherit (ghc.meta) license platforms;
+    platforms = lib.platforms.all;
+    inherit (ghc.meta) license;
   };
 
 } // lib.optionalAttrs targetPlatform.useAndroidPrebuilt {
diff --git a/pkgs/development/compilers/ghc/9.4.7.nix b/pkgs/development/compilers/ghc/9.4.7.nix
index e87f8fc3a9073..0ea5eca3ce9c6 100644
--- a/pkgs/development/compilers/ghc/9.4.7.nix
+++ b/pkgs/development/compilers/ghc/9.4.7.nix
@@ -1,6 +1,6 @@
 # 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
+{ lib, stdenv, pkgsBuildTarget, pkgsHostTarget, buildPackages, targetPackages
 
 # build-tools
 , bootPkgs
@@ -48,25 +48,37 @@
 
 , #  Whether to build sphinx documentation.
   enableDocs ? (
-    # Docs disabled if we are building on musl because it's a large task to keep
-    # all `sphinx` dependencies building in this environment.
-    !stdenv.buildPlatform.isMusl
+    # Docs disabled if we are building on musl or cross-building because it's a
+    # large task to keep all `sphinx` dependencies building in this environment.
+    (stdenv.buildPlatform == stdenv.hostPlatform && stdenv.targetPlatform == stdenv.hostPlatform)
+    && !stdenv.buildPlatform.isMusl
   )
 
 , enableHaddockProgram ?
     # Disabled for cross; see note [HADDOCK_DOCS].
-    (stdenv.targetPlatform == stdenv.hostPlatform)
+    (stdenv.buildPlatform == stdenv.hostPlatform && 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
+
+, # Whether to build an unregisterised version of GHC.
+  # GHC will normally auto-detect whether it can do a registered build, but this
+  # option will force it to do an unregistered build when set to true.
+  # See https://gitlab.haskell.org/ghc/ghc/-/wikis/building/unregisterised
+  # Registerised RV64 compiler produces programs that segfault
+  # See https://gitlab.haskell.org/ghc/ghc/-/issues/23957
+  enableUnregisterised ? stdenv.hostPlatform.isRiscV64 || stdenv.targetPlatform.isRiscV64
 }:
 
 assert !enableNativeBignum -> gmp != null;
 
 # Cross cannot currently build the `haddock` program for silly reasons,
 # see note [HADDOCK_DOCS].
-assert (stdenv.targetPlatform != stdenv.hostPlatform) -> !enableHaddockProgram;
+assert (stdenv.buildPlatform != stdenv.hostPlatform || stdenv.targetPlatform != stdenv.hostPlatform) -> !enableHaddockProgram;
+
+# GHC does not support building when all 3 platforms are different.
+assert stdenv.buildPlatform == stdenv.hostPlatform || stdenv.hostPlatform == stdenv.targetPlatform;
 
 let
   inherit (stdenv) buildPlatform hostPlatform targetPlatform;
@@ -131,7 +143,9 @@ let
     pkgsBuildTarget.targetPackages.stdenv.cc
   ] ++ lib.optional useLLVM buildTargetLlvmPackages.llvm;
 
+  buildCC = buildPackages.stdenv.cc;
   targetCC = builtins.head toolsForTarget;
+  installCC = pkgsHostTarget.targetPackages.stdenv.cc;
 
   # Sometimes we have to dispatch between the bintools wrapper and the unwrapped
   # derivation for certain tools depending on the platform.
@@ -163,14 +177,11 @@ let
     (lib.optionalString enableNativeBignum "-native-bignum")
   ];
 
-in
+  targetLibffi = if hostPlatform != targetPlatform
+    then targetPackages.libffi
+    else pkgsHostTarget.libffi;
 
-# 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;
+in
 
 stdenv.mkDerivation (rec {
   version = "9.4.7";
@@ -212,6 +223,9 @@ stdenv.mkDerivation (rec {
   # GHC needs the locale configured during the Haddock phase.
   LANG = "en_US.UTF-8";
 
+  # GHC is unable to build a cross-compiler without this set.
+  "NIX_CC_WRAPPER_TARGET_HOST_${buildCC.suffixSalt}" = 1;
+
   # GHC is a bit confused on its cross terminology.
   # TODO(@sternenseemann): investigate coreutils dependencies and pass absolute paths
   preConfigure = ''
@@ -240,6 +254,9 @@ stdenv.mkDerivation (rec {
     # LLVM backend on Darwin needs clang: https://downloads.haskell.org/~ghc/latest/docs/html/users_guide/codegens.html#llvm-code-generator-fllvm
     export CLANG="${buildTargetLlvmPackages.clang}/bin/${buildTargetLlvmPackages.clang.targetPrefix}clang"
   '' + ''
+    export CC_STAGE0="${buildCC}/bin/${buildCC.targetPrefix}cc"
+    export LD_STAGE0="${buildCC.bintools}/bin/${buildCC.bintools.targetPrefix}ld"
+    export AR_STAGE0="${buildCC.bintools.bintools}/bin/${buildCC.bintools.targetPrefix}ar"
 
     echo -n "${buildMK}" > mk/build.mk
 
@@ -280,18 +297,22 @@ stdenv.mkDerivation (rec {
       'MinBootGhcVersion="8.10"'
   '';
 
+  # Although it is usually correct to pass --host, we don't do that here because
+  # GHC's usage of build, host, and target is non-standard.
+  # See https://gitlab.haskell.org/ghc/ghc/-/wikis/building/cross-compiling
   # TODO(@Ericson2314): Always pass "--target" and always prefix.
-  configurePlatforms = [ "build" "host" ]
-    ++ lib.optional (targetPlatform != hostPlatform) "target";
+  configurePlatforms = [ "build" ]
+    ++ lib.optional (buildPlatform != hostPlatform || 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=${ncurses.out}/lib"
+    "--with-curses-includes=${buildPackages.ncurses.dev}/include"
+    "--with-curses-libraries=${buildPackages.ncurses.out}/lib"
   ] ++ lib.optionals (libffi != null) [
     "--with-system-libffi"
-    "--with-ffi-includes=${targetPackages.libffi.dev}/include"
-    "--with-ffi-libraries=${targetPackages.libffi.out}/lib"
+    "--with-ffi-includes=${targetLibffi.dev}/include"
+    "--with-ffi-libraries=${targetLibffi.out}/lib"
   ] ++ lib.optionals (targetPlatform == hostPlatform && !enableNativeBignum) [
     "--with-gmp-includes=${targetPackages.gmp.dev}/include"
     "--with-gmp-libraries=${targetPackages.gmp.out}/lib"
@@ -306,6 +327,8 @@ stdenv.mkDerivation (rec {
     "CONF_GCC_LINKER_OPTS_STAGE2=-fuse-ld=gold"
   ] ++ lib.optionals (disableLargeAddressSpace) [
     "--disable-large-address-space"
+  ] ++ lib.optionals enableUnregisterised [
+    "--enable-unregisterised"
   ];
 
   # Make sure we never relax`$PATH` and hooks support for compatibility.
@@ -353,6 +376,14 @@ stdenv.mkDerivation (rec {
   requiredSystemFeatures = [ "big-parallel" ];
 
   postInstall = ''
+    # Make the installed GHC use the host platform's tools.
+    sed -i $out/lib/${targetPrefix}${passthru.haskellCompilerName}/settings \
+      -e "s!$CC!${installCC}/bin/${installCC.targetPrefix}cc!g" \
+      -e "s!$CXX!${installCC}/bin/${installCC.targetPrefix}c++!g" \
+      -e "s!$LD!${installCC.bintools}/bin/${installCC.bintools.targetPrefix}ld${lib.optionalString useLdGold ".gold"}!g" \
+      -e "s!$AR!${installCC.bintools.bintools}/bin/${installCC.bintools.targetPrefix}ar!g" \
+      -e "s!$RANLIB!${installCC.bintools.bintools}/bin/${installCC.bintools.targetPrefix}ranlib!g"
+
     # Install the bash completion file.
     install -D -m 444 utils/completion/ghc.bash $out/share/bash-completion/completions/${targetPrefix}ghc
   '';
@@ -378,7 +409,8 @@ stdenv.mkDerivation (rec {
       guibou
     ] ++ lib.teams.haskell.members;
     timeout = 24 * 3600;
-    inherit (ghc.meta) license platforms;
+    platforms = lib.platforms.all;
+    inherit (ghc.meta) license;
   };
 
 } // lib.optionalAttrs targetPlatform.useAndroidPrebuilt {
diff --git a/pkgs/development/compilers/ghc/9.4.8.nix b/pkgs/development/compilers/ghc/9.4.8.nix
index 5ac2b60b1cd75..56f41620198e7 100644
--- a/pkgs/development/compilers/ghc/9.4.8.nix
+++ b/pkgs/development/compilers/ghc/9.4.8.nix
@@ -1,6 +1,6 @@
 # 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
+{ lib, stdenv, pkgsBuildTarget, pkgsHostTarget, buildPackages, targetPackages
 
 # build-tools
 , bootPkgs
@@ -48,25 +48,37 @@
 
 , #  Whether to build sphinx documentation.
   enableDocs ? (
-    # Docs disabled if we are building on musl because it's a large task to keep
-    # all `sphinx` dependencies building in this environment.
-    !stdenv.buildPlatform.isMusl
+    # Docs disabled if we are building on musl or cross-building because it's a
+    # large task to keep all `sphinx` dependencies building in this environment.
+    (stdenv.buildPlatform == stdenv.hostPlatform && stdenv.targetPlatform == stdenv.hostPlatform)
+    && !stdenv.buildPlatform.isMusl
   )
 
 , enableHaddockProgram ?
     # Disabled for cross; see note [HADDOCK_DOCS].
-    (stdenv.targetPlatform == stdenv.hostPlatform)
+    (stdenv.buildPlatform == stdenv.hostPlatform && 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
+
+, # Whether to build an unregisterised version of GHC.
+  # GHC will normally auto-detect whether it can do a registered build, but this
+  # option will force it to do an unregistered build when set to true.
+  # See https://gitlab.haskell.org/ghc/ghc/-/wikis/building/unregisterised
+  # Registerised RV64 compiler produces programs that segfault
+  # See https://gitlab.haskell.org/ghc/ghc/-/issues/23957
+  enableUnregisterised ? stdenv.hostPlatform.isRiscV64 || stdenv.targetPlatform.isRiscV64
 }:
 
 assert !enableNativeBignum -> gmp != null;
 
 # Cross cannot currently build the `haddock` program for silly reasons,
 # see note [HADDOCK_DOCS].
-assert (stdenv.targetPlatform != stdenv.hostPlatform) -> !enableHaddockProgram;
+assert (stdenv.buildPlatform != stdenv.hostPlatform || stdenv.targetPlatform != stdenv.hostPlatform) -> !enableHaddockProgram;
+
+# GHC does not support building when all 3 platforms are different.
+assert stdenv.buildPlatform == stdenv.hostPlatform || stdenv.hostPlatform == stdenv.targetPlatform;
 
 let
   inherit (stdenv) buildPlatform hostPlatform targetPlatform;
@@ -131,7 +143,9 @@ let
     pkgsBuildTarget.targetPackages.stdenv.cc
   ] ++ lib.optional useLLVM buildTargetLlvmPackages.llvm;
 
+  buildCC = buildPackages.stdenv.cc;
   targetCC = builtins.head toolsForTarget;
+  installCC = pkgsHostTarget.targetPackages.stdenv.cc;
 
   # Sometimes we have to dispatch between the bintools wrapper and the unwrapped
   # derivation for certain tools depending on the platform.
@@ -163,14 +177,11 @@ let
     (lib.optionalString enableNativeBignum "-native-bignum")
   ];
 
-in
+  targetLibffi = if hostPlatform != targetPlatform
+    then targetPackages.libffi
+    else pkgsHostTarget.libffi;
 
-# 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;
+in
 
 stdenv.mkDerivation (rec {
   version = "9.4.8";
@@ -212,6 +223,9 @@ stdenv.mkDerivation (rec {
   # GHC needs the locale configured during the Haddock phase.
   LANG = "en_US.UTF-8";
 
+  # GHC is unable to build a cross-compiler without this set.
+  "NIX_CC_WRAPPER_TARGET_HOST_${buildCC.suffixSalt}" = 1;
+
   # GHC is a bit confused on its cross terminology.
   # TODO(@sternenseemann): investigate coreutils dependencies and pass absolute paths
   preConfigure = ''
@@ -240,6 +254,9 @@ stdenv.mkDerivation (rec {
     # LLVM backend on Darwin needs clang: https://downloads.haskell.org/~ghc/latest/docs/html/users_guide/codegens.html#llvm-code-generator-fllvm
     export CLANG="${buildTargetLlvmPackages.clang}/bin/${buildTargetLlvmPackages.clang.targetPrefix}clang"
   '' + ''
+    export CC_STAGE0="${buildCC}/bin/${buildCC.targetPrefix}cc"
+    export LD_STAGE0="${buildCC.bintools}/bin/${buildCC.bintools.targetPrefix}ld"
+    export AR_STAGE0="${buildCC.bintools.bintools}/bin/${buildCC.bintools.targetPrefix}ar"
 
     echo -n "${buildMK}" > mk/build.mk
 
@@ -280,18 +297,22 @@ stdenv.mkDerivation (rec {
       'MinBootGhcVersion="8.10"'
   '';
 
+  # Although it is usually correct to pass --host, we don't do that here because
+  # GHC's usage of build, host, and target is non-standard.
+  # See https://gitlab.haskell.org/ghc/ghc/-/wikis/building/cross-compiling
   # TODO(@Ericson2314): Always pass "--target" and always prefix.
-  configurePlatforms = [ "build" "host" ]
-    ++ lib.optional (targetPlatform != hostPlatform) "target";
+  configurePlatforms = [ "build" ]
+    ++ lib.optional (buildPlatform != hostPlatform || 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=${ncurses.out}/lib"
+    "--with-curses-includes=${buildPackages.ncurses.dev}/include"
+    "--with-curses-libraries=${buildPackages.ncurses.out}/lib"
   ] ++ lib.optionals (libffi != null) [
     "--with-system-libffi"
-    "--with-ffi-includes=${targetPackages.libffi.dev}/include"
-    "--with-ffi-libraries=${targetPackages.libffi.out}/lib"
+    "--with-ffi-includes=${targetLibffi.dev}/include"
+    "--with-ffi-libraries=${targetLibffi.out}/lib"
   ] ++ lib.optionals (targetPlatform == hostPlatform && !enableNativeBignum) [
     "--with-gmp-includes=${targetPackages.gmp.dev}/include"
     "--with-gmp-libraries=${targetPackages.gmp.out}/lib"
@@ -306,6 +327,8 @@ stdenv.mkDerivation (rec {
     "CONF_GCC_LINKER_OPTS_STAGE2=-fuse-ld=gold"
   ] ++ lib.optionals (disableLargeAddressSpace) [
     "--disable-large-address-space"
+  ] ++ lib.optionals enableUnregisterised [
+    "--enable-unregisterised"
   ];
 
   # Make sure we never relax`$PATH` and hooks support for compatibility.
@@ -353,6 +376,14 @@ stdenv.mkDerivation (rec {
   requiredSystemFeatures = [ "big-parallel" ];
 
   postInstall = ''
+    # Make the installed GHC use the host platform's tools.
+    sed -i $out/lib/${targetPrefix}${passthru.haskellCompilerName}/settings \
+      -e "s!$CC!${installCC}/bin/${installCC.targetPrefix}cc!g" \
+      -e "s!$CXX!${installCC}/bin/${installCC.targetPrefix}c++!g" \
+      -e "s!$LD!${installCC.bintools}/bin/${installCC.bintools.targetPrefix}ld${lib.optionalString useLdGold ".gold"}!g" \
+      -e "s!$AR!${installCC.bintools.bintools}/bin/${installCC.bintools.targetPrefix}ar!g" \
+      -e "s!$RANLIB!${installCC.bintools.bintools}/bin/${installCC.bintools.targetPrefix}ranlib!g"
+
     # Install the bash completion file.
     install -D -m 444 utils/completion/ghc.bash $out/share/bash-completion/completions/${targetPrefix}ghc
   '';
@@ -378,7 +409,8 @@ stdenv.mkDerivation (rec {
       guibou
     ] ++ lib.teams.haskell.members;
     timeout = 24 * 3600;
-    inherit (ghc.meta) license platforms;
+    platforms = lib.platforms.all;
+    inherit (ghc.meta) license;
   };
 
 } // lib.optionalAttrs targetPlatform.useAndroidPrebuilt {
diff --git a/pkgs/development/compilers/ghc/common-hadrian.nix b/pkgs/development/compilers/ghc/common-hadrian.nix
index 465db3a252964..c5eeb10017615 100644
--- a/pkgs/development/compilers/ghc/common-hadrian.nix
+++ b/pkgs/development/compilers/ghc/common-hadrian.nix
@@ -12,6 +12,7 @@
 , stdenv
 , pkgsBuildTarget
 , pkgsHostTarget
+, buildPackages
 , targetPackages
 
 # build-tools
@@ -164,18 +165,31 @@
 , #  Whether to build sphinx documentation.
   # TODO(@sternenseemann): Hadrian ignores the --docs flag if finalStage = Stage1
   enableDocs ? (
-    # Docs disabled if we are building on musl because it's a large task to keep
-    # all `sphinx` dependencies building in this environment.
-    !stdenv.buildPlatform.isMusl
+    # Docs disabled if we are building on musl or cross-building because it's a
+    # large task to keep all `sphinx` dependencies building in this environment.
+    (stdenv.buildPlatform == stdenv.hostPlatform && stdenv.targetPlatform == stdenv.hostPlatform)
+    && !stdenv.buildPlatform.isMusl
   )
 
 , # 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
+
+, # Whether to build an unregisterised version of GHC.
+  # GHC will normally auto-detect whether it can do a registered build, but this
+  # option will force it to do an unregistered build when set to true.
+  # See https://gitlab.haskell.org/ghc/ghc/-/wikis/building/unregisterised
+  enableUnregisterised ? false
 }:
 
 assert !enableNativeBignum -> gmp != null;
 
+# GHC does not support building when all 3 platforms are different.
+assert stdenv.buildPlatform == stdenv.hostPlatform || stdenv.hostPlatform == stdenv.targetPlatform;
+
+# It is currently impossible to cross-compile GHC with Hadrian.
+assert stdenv.buildPlatform == stdenv.hostPlatform;
+
 let
   inherit (stdenv) buildPlatform hostPlatform targetPlatform;
 
@@ -215,7 +229,9 @@ let
      else pkgsBuildTarget.targetPackages.stdenv.cc)
   ] ++ lib.optional useLLVM buildTargetLlvmPackages.llvm;
 
+  buildCC = buildPackages.stdenv.cc;
   targetCC = builtins.head toolsForTarget;
+  installCC = pkgsHostTarget.targetPackages.stdenv.cc;
 
   # Sometimes we have to dispatch between the bintools wrapper and the unwrapped
   # derivation for certain tools depending on the platform.
@@ -247,6 +263,13 @@ let
     (lib.optionalString enableNativeBignum "-native-bignum")
   ];
 
+  targetLibffi = if hostPlatform != targetPlatform
+    then targetPackages.libffi
+    else pkgsHostTarget.libffi;
+
+  # Our Cabal compiler name
+  haskellCompilerName = "ghc-${version}";
+
 in
 
 # C compiler, bintools and LLVM are used at build time, but will also leak into
@@ -286,12 +309,18 @@ stdenv.mkDerivation ({
   # GHC needs the locale configured during the Haddock phase.
   LANG = "en_US.UTF-8";
 
+  # GHC is unable to build a cross-compiler without this set.
+  "NIX_CC_WRAPPER_TARGET_HOST_${buildCC.suffixSalt}" = 1;
+
   # 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_}=''${!env}"
     done
+    export CC_STAGE0="${buildCC}/bin/${buildCC.targetPrefix}cc"
+    export LD_STAGE0="${buildCC.bintools}/bin/${buildCC.bintools.targetPrefix}ld"
+    export AR_STAGE0="${buildCC.bintools.bintools}/bin/${buildCC.bintools.targetPrefix}ar"
     # GHC is a bit confused on its cross terminology, as these would normally be
     # the *host* tools.
     export CC="${targetCC}/bin/${targetCC.targetPrefix}cc"
@@ -379,11 +408,12 @@ stdenv.mkDerivation ({
   # `--with` flags for libraries needed for RTS linker
   configureFlags = [
     "--datadir=$doc/share/doc/ghc"
-    "--with-curses-includes=${ncurses.dev}/include" "--with-curses-libraries=${ncurses.out}/lib"
+    "--with-curses-includes=${buildPackages.ncurses.dev}/include"
+    "--with-curses-libraries=${buildPackages.ncurses.out}/lib"
   ] ++ lib.optionals (libffi != null && !targetPlatform.isGhcjs) [
     "--with-system-libffi"
-    "--with-ffi-includes=${targetPackages.libffi.dev}/include"
-    "--with-ffi-libraries=${targetPackages.libffi.out}/lib"
+    "--with-ffi-includes=${targetLibffi.dev}/include"
+    "--with-ffi-libraries=${targetLibffi.out}/lib"
   ] ++ lib.optionals (targetPlatform == hostPlatform && !enableNativeBignum) [
     "--with-gmp-includes=${targetPackages.gmp.dev}/include"
     "--with-gmp-libraries=${targetPackages.gmp.out}/lib"
@@ -408,6 +438,8 @@ stdenv.mkDerivation ({
     # https://gitlab.haskell.org/ghc/ghc/-/issues/23188
     # https://github.com/haskell/cabal/issues/8882
     "fp_cv_prog_ar_supports_dash_l=no"
+  ] ++ lib.optionals enableUnregisterised [
+    "--enable-unregisterised"
   ];
 
   # Make sure we never relax`$PATH` and hooks support for compatibility.
@@ -499,19 +531,24 @@ stdenv.mkDerivation ({
     # leave bindist directory
     popd
 
+    # Make the installed GHC use the host platform's tools.
+    sed -i $out/lib/${targetPrefix}${haskellCompilerName}/lib/settings \
+      -e "s!$CC!${installCC}/bin/${installCC.targetPrefix}cc!g" \
+      -e "s!$CXX!${installCC}/bin/${installCC.targetPrefix}c++!g" \
+      -e "s!$LD!${installCC.bintools}/bin/${installCC.bintools.targetPrefix}ld${lib.optionalString useLdGold ".gold"}!g" \
+      -e "s!$AR!${installCC.bintools.bintools}/bin/${installCC.bintools.targetPrefix}ar!g" \
+      -e "s!$RANLIB!${installCC.bintools.bintools}/bin/${installCC.bintools.targetPrefix}ranlib!g"
+
     # Install the bash completion file.
     install -Dm 644 utils/completion/ghc.bash $out/share/bash-completion/completions/${targetPrefix}ghc
   '';
 
   passthru = {
-    inherit bootPkgs targetPrefix;
+    inherit bootPkgs targetPrefix haskellCompilerName;
 
     inherit llvmPackages;
     inherit enableShared;
 
-    # Our Cabal compiler name
-    haskellCompilerName = "ghc-${version}";
-
     # Expose hadrian used for bootstrapping, for debugging purposes
     inherit hadrian;
 
@@ -527,7 +564,8 @@ stdenv.mkDerivation ({
       guibou
     ] ++ lib.teams.haskell.members;
     timeout = 24 * 3600;
-    inherit (ghc.meta) license platforms;
+    platforms = lib.platforms.all;
+    inherit (ghc.meta) license;
     # https://github.com/NixOS/nixpkgs/issues/208959
     broken =
       (lib.versionAtLeast version "9.6" && lib.versionOlder version "9.8")
diff --git a/pkgs/test/cross/default.nix b/pkgs/test/cross/default.nix
index bd233db4cd50f..7f5a777794d5c 100644
--- a/pkgs/test/cross/default.nix
+++ b/pkgs/test/cross/default.nix
@@ -146,6 +146,8 @@ let
     pkgs.pkgsCross.mips64el-linux-gnuabi64.stdenv
     pkgs.pkgsCross.mips64el-linux-gnuabin32.stdenv
     pkgs.pkgsCross.mingwW64.stdenv
+    # Unlike later versions, cross-compiled 8.10.7 can reliably bootstrap a native build
+    pkgs.pkgsCross.riscv64.haskell.compiler.integer-simple.ghc8107
 
   ] ++ lib.optionals (with pkgs.stdenv.buildPlatform; isx86_64 && isLinux) [
     # Musl-to-glibc cross on the same architecture tends to turn up
diff --git a/pkgs/top-level/haskell-packages.nix b/pkgs/top-level/haskell-packages.nix
index ddfd8146b53d0..5568cf80bed2d 100644
--- a/pkgs/top-level/haskell-packages.nix
+++ b/pkgs/top-level/haskell-packages.nix
@@ -1,4 +1,4 @@
-{ buildPackages, pkgsBuildTarget, pkgs, newScope, stdenv }:
+{ buildPackages, pkgsBuildBuild, pkgsBuildTarget, pkgs, newScope, stdenv }:
 
 let
   # These are attributes in compiler that support integer-simple.
@@ -52,7 +52,8 @@ in {
 
   package-list = callPackage ../development/haskell-modules/package-list.nix {};
 
-  compiler = {
+  # Always get boot compilers from `pkgsBuildBuild`
+  compiler = let bb = pkgsBuildBuild.haskell; in {
     ghc865Binary = callPackage ../development/compilers/ghc/8.6.5-binary.nix {
       # Should be llvmPackages_6 which has been removed from nixpkgs
       llvmPackages = null;
@@ -73,11 +74,11 @@ in {
     ghc8107 = callPackage ../development/compilers/ghc/8.10.7.nix {
       bootPkgs =
         # the oldest ghc with aarch64-darwin support is 8.10.5
-        if stdenv.hostPlatform.isPower64 && stdenv.hostPlatform.isLittleEndian then
+        if stdenv.buildPlatform.isPower64 && stdenv.buildPlatform.isLittleEndian then
           # to my (@a-m-joseph) knowledge there are no newer official binaries for this platform
-          packages.ghc865Binary
+          bb.packages.ghc865Binary
         else
-          packages.ghc8107Binary;
+          bb.packages.ghc8107Binary;
       inherit (buildPackages.python3Packages) sphinx;
       # Need to use apple's patched xattr until
       # https://github.com/xattr/xattr/issues/44 and
@@ -90,10 +91,10 @@ in {
     ghc902 = callPackage ../development/compilers/ghc/9.0.2.nix {
       bootPkgs =
         # the oldest ghc with aarch64-darwin support is 8.10.5
-        if stdenv.hostPlatform.isPower64 && stdenv.hostPlatform.isLittleEndian then
-          packages.ghc810
+        if stdenv.buildPlatform.isPower64 && stdenv.buildPlatform.isLittleEndian then
+          bb.packages.ghc810
         else
-          packages.ghc8107Binary;
+          bb.packages.ghc8107Binary;
       inherit (buildPackages.python3Packages) sphinx;
       inherit (buildPackages.darwin) autoSignDarwinBinariesHook xattr;
       buildTargetLlvmPackages = pkgsBuildTarget.llvmPackages_12;
@@ -102,10 +103,10 @@ in {
     ghc90 = compiler.ghc902;
     ghc925 = callPackage ../development/compilers/ghc/9.2.5.nix {
       bootPkgs =
-        if stdenv.hostPlatform.isPower64 && stdenv.hostPlatform.isLittleEndian then
-          packages.ghc810
+        if stdenv.buildPlatform.isPower64 && stdenv.buildPlatform.isLittleEndian then
+          bb.packages.ghc810
         else
-          packages.ghc8107Binary;
+          bb.packages.ghc8107Binary;
       inherit (buildPackages.python3Packages) sphinx;
       # Need to use apple's patched xattr until
       # https://github.com/xattr/xattr/issues/44 and
@@ -116,10 +117,10 @@ in {
     };
     ghc926 = callPackage ../development/compilers/ghc/9.2.6.nix {
       bootPkgs =
-        if stdenv.hostPlatform.isPower64 && stdenv.hostPlatform.isLittleEndian then
-          packages.ghc810
+        if stdenv.buildPlatform.isPower64 && stdenv.buildPlatform.isLittleEndian then
+          bb.packages.ghc810
         else
-          packages.ghc8107Binary;
+          bb.packages.ghc8107Binary;
       inherit (buildPackages.python3Packages) sphinx;
       # Need to use apple's patched xattr until
       # https://github.com/xattr/xattr/issues/44 and
@@ -130,10 +131,10 @@ in {
     };
     ghc927 = callPackage ../development/compilers/ghc/9.2.7.nix {
       bootPkgs =
-        if stdenv.hostPlatform.isPower64 && stdenv.hostPlatform.isLittleEndian then
-          packages.ghc810
+        if stdenv.buildPlatform.isPower64 && stdenv.buildPlatform.isLittleEndian then
+          bb.packages.ghc810
         else
-          packages.ghc8107Binary;
+          bb.packages.ghc8107Binary;
       inherit (buildPackages.python3Packages) sphinx;
       # Need to use apple's patched xattr until
       # https://github.com/xattr/xattr/issues/44 and
@@ -144,10 +145,10 @@ in {
     };
     ghc928 = callPackage ../development/compilers/ghc/9.2.8.nix {
       bootPkgs =
-        if stdenv.hostPlatform.isPower64 && stdenv.hostPlatform.isLittleEndian then
-          packages.ghc810
+        if stdenv.buildPlatform.isPower64 && stdenv.buildPlatform.isLittleEndian then
+          bb.packages.ghc810
         else
-          packages.ghc8107Binary;
+          bb.packages.ghc8107Binary;
       inherit (buildPackages.python3Packages) sphinx;
       # Need to use apple's patched xattr until
       # https://github.com/xattr/xattr/issues/44 and
@@ -164,14 +165,14 @@ in {
         # 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
+        if stdenv.buildPlatform.isAarch then
           # TODO(@sternenseemann): package bindist
-          packages.ghc902
+          bb.packages.ghc902
         # No suitable bindists for powerpc64le
-        else if stdenv.hostPlatform.isPower64 && stdenv.hostPlatform.isLittleEndian then
-          packages.ghc902
+        else if stdenv.buildPlatform.isPower64 && stdenv.buildPlatform.isLittleEndian then
+          bb.packages.ghc902
         else
-          packages.ghc8107Binary;
+          bb.packages.ghc8107Binary;
       inherit (buildPackages.python3Packages) sphinx;
       # Need to use apple's patched xattr until
       # https://github.com/xattr/xattr/issues/44 and
@@ -188,14 +189,14 @@ in {
         # 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
+        if stdenv.buildPlatform.isAarch then
           # TODO(@sternenseemann): package bindist
-          packages.ghc902
+          bb.packages.ghc902
         # No suitable bindists for powerpc64le
-        else if stdenv.hostPlatform.isPower64 && stdenv.hostPlatform.isLittleEndian then
-          packages.ghc902
+        else if stdenv.buildPlatform.isPower64 && stdenv.buildPlatform.isLittleEndian then
+          bb.packages.ghc902
         else
-          packages.ghc8107Binary;
+          bb.packages.ghc8107Binary;
       inherit (buildPackages.python3Packages) sphinx;
       # Need to use apple's patched xattr until
       # https://github.com/xattr/xattr/issues/44 and
@@ -212,14 +213,14 @@ in {
         # 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
+        if stdenv.buildPlatform.isAarch then
           # TODO(@sternenseemann): package bindist
-          packages.ghc902
+          bb.packages.ghc902
         # No suitable bindists for powerpc64le
-        else if stdenv.hostPlatform.isPower64 && stdenv.hostPlatform.isLittleEndian then
-          packages.ghc902
+        else if stdenv.buildPlatform.isPower64 && stdenv.buildPlatform.isLittleEndian then
+          bb.packages.ghc902
         else
-          packages.ghc8107Binary;
+          bb.packages.ghc8107Binary;
       inherit (buildPackages.python3Packages) sphinx;
       # Need to use apple's patched xattr until
       # https://github.com/xattr/xattr/issues/44 and
@@ -236,14 +237,14 @@ in {
         # 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
+        if stdenv.buildPlatform.isAarch then
           # TODO(@sternenseemann): package bindist
-          packages.ghc902
+          bb.packages.ghc902
         # No suitable bindists for powerpc64le
-        else if stdenv.hostPlatform.isPower64 && stdenv.hostPlatform.isLittleEndian then
-          packages.ghc902
+        else if stdenv.buildPlatform.isPower64 && stdenv.buildPlatform.isLittleEndian then
+          bb.packages.ghc902
         else
-          packages.ghc8107Binary;
+          bb.packages.ghc8107Binary;
       inherit (buildPackages.python3Packages) sphinx;
       # Need to use apple's patched xattr until
       # https://github.com/xattr/xattr/issues/44 and
@@ -257,12 +258,12 @@ in {
     ghc963 = callPackage ../development/compilers/ghc/9.6.3.nix {
       bootPkgs =
         # For GHC 9.2 no armv7l bindists are available.
-        if stdenv.hostPlatform.isAarch32 then
-          packages.ghc928
-        else if stdenv.hostPlatform.isPower64 && stdenv.hostPlatform.isLittleEndian then
-          packages.ghc928
+        if stdenv.buildPlatform.isAarch32 then
+          bb.packages.ghc928
+        else if stdenv.buildPlatform.isPower64 && stdenv.buildPlatform.isLittleEndian then
+          bb.packages.ghc928
         else
-          packages.ghc924Binary;
+          bb.packages.ghc924Binary;
       inherit (buildPackages.python3Packages) sphinx;
       # Need to use apple's patched xattr until
       # https://github.com/xattr/xattr/issues/44 and
@@ -275,12 +276,12 @@ in {
     ghc964 = callPackage ../development/compilers/ghc/9.6.4.nix {
       bootPkgs =
         # For GHC 9.2 no armv7l bindists are available.
-        if stdenv.hostPlatform.isAarch32 then
-          packages.ghc928
-        else if stdenv.hostPlatform.isPower64 && stdenv.hostPlatform.isLittleEndian then
-          packages.ghc928
+        if stdenv.buildPlatform.isAarch32 then
+          bb.packages.ghc928
+        else if stdenv.buildPlatform.isPower64 && stdenv.buildPlatform.isLittleEndian then
+          bb.packages.ghc928
         else
-          packages.ghc924Binary;
+          bb.packages.ghc924Binary;
       inherit (buildPackages.python3Packages) sphinx;
       # Need to use apple's patched xattr until
       # https://github.com/xattr/xattr/issues/44 and
@@ -294,19 +295,19 @@ in {
     ghc981 = callPackage ../development/compilers/ghc/9.8.1.nix {
       bootPkgs =
         # For GHC 9.6 no armv7l bindists are available.
-        if stdenv.hostPlatform.isAarch32 then
-          packages.ghc963
-        else if stdenv.hostPlatform.isPower64 && stdenv.hostPlatform.isLittleEndian then
-          packages.ghc963
-        else if stdenv.hostPlatform.isDarwin then
+        if stdenv.buildPlatform.isAarch32 then
+          bb.packages.ghc963
+        else if stdenv.buildPlatform.isPower64 && stdenv.buildPlatform.isLittleEndian then
+          bb.packages.ghc963
+        else if stdenv.buildPlatform.isDarwin then
           # it seems like the GHC 9.6.* bindists are built with a different
           # toolchain than we are using (which I'm guessing from the fact
           # that 9.6.4 bindists pass linker flags our ld doesn't support).
           # With both 9.6.3 and 9.6.4 binary it is impossible to link against
           # the clock package (probably a hsc2hs problem).
-          packages.ghc963
+          bb.packages.ghc963
         else
-          packages.ghc963Binary;
+          bb.packages.ghc963Binary;
       inherit (buildPackages.python3Packages) sphinx;
       # Need to use apple's patched xattr until
       # https://github.com/xattr/xattr/issues/44 and
@@ -319,19 +320,19 @@ in {
     ghc982 = callPackage ../development/compilers/ghc/9.8.2.nix {
       bootPkgs =
         # For GHC 9.6 no armv7l bindists are available.
-        if stdenv.hostPlatform.isAarch32 then
-          packages.ghc963
-        else if stdenv.hostPlatform.isPower64 && stdenv.hostPlatform.isLittleEndian then
-          packages.ghc963
-        else if stdenv.hostPlatform.isDarwin then
+        if stdenv.buildPlatform.isAarch32 then
+          bb.packages.ghc963
+        else if stdenv.buildPlatform.isPower64 && stdenv.buildPlatform.isLittleEndian then
+          bb.packages.ghc963
+        else if stdenv.buildPlatform.isDarwin then
           # it seems like the GHC 9.6.* bindists are built with a different
           # toolchain than we are using (which I'm guessing from the fact
           # that 9.6.4 bindists pass linker flags our ld doesn't support).
           # With both 9.6.3 and 9.6.4 binary it is impossible to link against
           # the clock package (probably a hsc2hs problem).
-          packages.ghc963
+          bb.packages.ghc963
         else
-          packages.ghc963Binary;
+          bb.packages.ghc963Binary;
       inherit (buildPackages.python3Packages) sphinx;
       # Need to use apple's patched xattr until
       # https://github.com/xattr/xattr/issues/44 and
@@ -345,19 +346,19 @@ in {
     ghcHEAD = callPackage ../development/compilers/ghc/head.nix {
       bootPkgs =
         # For GHC 9.6 no armv7l bindists are available.
-        if stdenv.hostPlatform.isAarch32 then
-          packages.ghc963
-        else if stdenv.hostPlatform.isPower64 && stdenv.hostPlatform.isLittleEndian then
-          packages.ghc963
-        else if stdenv.hostPlatform.isDarwin then
+        if stdenv.buildPlatform.isAarch32 then
+          bb.packages.ghc963
+        else if stdenv.buildPlatform.isPower64 && stdenv.buildPlatform.isLittleEndian then
+          bb.packages.ghc963
+        else if stdenv.buildPlatform.isDarwin then
           # it seems like the GHC 9.6.* bindists are built with a different
           # toolchain than we are using (which I'm guessing from the fact
           # that 9.6.4 bindists pass linker flags our ld doesn't support).
           # With both 9.6.3 and 9.6.4 binary it is impossible to link against
           # the clock package (probably a hsc2hs problem).
-          packages.ghc963
+          bb.packages.ghc963
         else
-          packages.ghc963Binary;
+          bb.packages.ghc963Binary;
       inherit (buildPackages.python3Packages) sphinx;
       # Need to use apple's patched xattr until
       # https://github.com/xattr/xattr/issues/44 and
@@ -370,7 +371,7 @@ in {
 
     ghcjs = compiler.ghcjs810;
     ghcjs810 = callPackage ../development/compilers/ghcjs/8.10 {
-      bootPkgs = packages.ghc810;
+      bootPkgs = bb.packages.ghc810;
       ghcjsSrcJson = ../development/compilers/ghcjs/8.10/git.json;
       stage0 = ../development/compilers/ghcjs/8.10/stage0.nix;
     };