cudaPackages: enable cross-compilation (take two)

pkgs/development/compilers/gcc/common/builder.nix

@@ -1,6 +1,7 @@
 { lib
 , stdenv
 , enableMultilib
+, targetConfig
 }:
 
 let
@@ -196,6 +197,13 @@ originalAttrs: (stdenv.mkDerivation (finalAttrs: originalAttrs // {
     mkdir -p "$out/''${targetConfig}/lib"
     mkdir -p "''${!outputLib}/''${targetConfig}/lib"
   '' +
+  # if cross-compiling, link from $lib/lib to $lib/${targetConfig}.
+  # since native-compiles have $lib/lib as a directory (not a
+  # symlink), this ensures that in every case we can assume that
+  # $lib/lib contains the .so files
+  lib.optionalString (with stdenv; targetPlatform.config != hostPlatform.config) ''
+    ln -Ts "''${!outputLib}/''${targetConfig}/lib" $lib/lib
+  '' +
   # Make `lib64` symlinks to `lib`.
   lib.optionalString (!enableMultilib && stdenv.hostPlatform.is64bit && !stdenv.hostPlatform.isMips64n32) ''
     ln -s lib "$out/''${targetConfig}/lib64"

pkgs/development/compilers/gcc/common/libgcc.nix

@@ -83,10 +83,6 @@ in
     lib.optionalString (!langC) ''
       rm -f $out/lib/libgcc_s.so*
     ''
-    + lib.optionalString (hostPlatform != targetPlatform) ''
-      mkdir -p $lib/lib/
-      ln -s ${targetPlatformSlash}lib $lib/lib
-    ''
 
     # TODO(amjoseph): remove the `libgcc_s.so` symlinks below and replace them
     # with a `-L${gccForLibs.libgcc}/lib` in cc-wrapper's

pkgs/development/compilers/gcc/default.nix

@@ -103,6 +103,7 @@ let inherit version;
     disableBootstrap = atLeast11 && !stdenv.hostPlatform.isDarwin && (atLeast12 -> !profiledCompiler);
 
     inherit (stdenv) buildPlatform hostPlatform targetPlatform;
+    targetConfig = if targetPlatform != hostPlatform then targetPlatform.config else null;
 
     patches = callFile ./patches {};
 
@@ -124,6 +125,7 @@ let inherit version;
         buildPlatform
         hostPlatform
         targetPlatform
+        targetConfig
         patches
         crossMingw
         stageNameAddon
@@ -329,7 +331,7 @@ lib.pipe ((callFile ./common/builder.nix {}) ({
     ++ optional (is7 && targetPlatform.isAarch64) "--enable-fix-cortex-a53-843419"
     ++ optional (is7 && targetPlatform.isNetBSD) "--disable-libcilkrts";
 
-  targetConfig = if targetPlatform != hostPlatform then targetPlatform.config else null;
+  inherit targetConfig;
 
   buildFlags =
     # we do not yet have Nix-driven profiling

pkgs/development/cuda-modules/backend-stdenv.nix

@@ -3,10 +3,8 @@
   nvccCompatibilities,
   cudaVersion,
   pkgs,
-  overrideCC,
   stdenv,
-  wrapCCWith,
-  stdenvAdapters,
+  stdenvAdapters
 }:
 
 let

pkgs/development/cuda-modules/cuda-library-samples/extension.nix

@@ -1,8 +1,10 @@
-{hostPlatform, lib}:
+{backendStdenv, lib}:
 let
+  inherit (backendStdenv.hostPlatform) isx86_64 isLinux;
+
   # Samples are built around the CUDA Toolkit, which is not available for
   # aarch64. Check for both CUDA version and platform.
-  platformIsSupported = hostPlatform.isx86_64 && hostPlatform.isLinux;
+  platformIsSupported = isx86_64 && isLinux;
 
   # Build our extension
   extension =

pkgs/development/cuda-modules/cuda-library-samples/generic.nix

@@ -76,7 +76,7 @@ in
       # CUTENSOR_ROOT is double escaped
       postPatch = ''
         substituteInPlace CMakeLists.txt \
-          --replace "\''${CUTENSOR_ROOT}/include" "${cutensor.dev}/include"
+          --replace-fail "\''${CUTENSOR_ROOT}/include" "${cutensor.dev}/include"
       '';
 
       CUTENSOR_ROOT = cutensor;

pkgs/development/cuda-modules/cuda-samples/extension.nix

@@ -1,6 +1,6 @@
 {
+  backendStdenv,
   cudaVersion,
-  hostPlatform,
   lib,
 }:
 let
@@ -26,7 +26,7 @@ let
   # Samples are built around the CUDA Toolkit, which is not available for
   # aarch64. Check for both CUDA version and platform.
   cudaVersionIsSupported = cudaVersionToHash ? ${cudaVersion};
-  platformIsSupported = hostPlatform.isx86_64;
+  platformIsSupported = backendStdenv.hostPlatform.isx86_64;
   isSupported = cudaVersionIsSupported && platformIsSupported;
 
   # Build our extension

pkgs/development/cuda-modules/cuda-samples/generic.nix

@@ -14,6 +14,7 @@
 }:
 let
   inherit (lib) lists strings;
+  inherit (backendStdenv.hostPlatform.parsed) cpu kernel;
 in
 backendStdenv.mkDerivation (
   finalAttrs: {
@@ -64,7 +65,7 @@ backendStdenv.mkDerivation (
     installPhase = ''
       runHook preInstall
 
-      install -Dm755 -t $out/bin bin/${backendStdenv.hostPlatform.parsed.cpu.name}/${backendStdenv.hostPlatform.parsed.kernel.name}/release/*
+      install -Dm755 -t $out/bin bin/${cpu.name}/${kernel.name}/release/*
 
       runHook postInstall
     '';