dockerTools: Always cross compile for another arch in the cross example

The example fails to build on aarch64, so lets cross build for gnu64.

1 files changed, 7 insertions, 2 deletions

diff --git a/pkgs/build-support/docker/examples.nix b/pkgs/build-support/docker/examples.nix
index cd91c721241..3f30f1a2adb 100644
--- a/pkgs/build-support/docker/examples.nix
+++ b/pkgs/build-support/docker/examples.nix
@@ -408,10 +408,15 @@ rec {
     };
 
   # basic example, with cross compilation
-  cross-aarch64 = pkgsCross.aarch64-multiplatform.dockerTools.buildImage {
+  cross = let
+    # Cross compile for x86_64 if on aarch64
+    crossPkgs =
+      if pkgs.system == "aarch64-linux" then pkgsCross.gnu64
+      else pkgsCross.aarch64-multiplatform;
+  in crossPkgs.dockerTools.buildImage {
     name = "hello-cross";
     tag = "latest";
-    contents = pkgsCross.aarch64-multiplatform.hello;
+    contents = crossPkgs.hello;
   };
 
 }