sdl3: fix cross compilation

[uninsane]

• fixes nix-build -A pkgsCross.aarch64-multiplatform.sdl3

may require cherry-picking this ibusMinimal buildfix as sdl3 has ibusMinimal as a build input, but these PRs can be merged in any order.

Things done

• Built on platform(s)
  • [x] x86_64-linux
  • [ ] aarch64-linux
  • [ ] x86_64-darwin
  • [ ] aarch64-darwin
• For non-Linux: Is sandboxing enabled in nix.conf? (See Nix manual)
  • [ ] sandbox = relaxed
  • [ ] sandbox = true
• [ ] Tested, as applicable:
  • NixOS test(s) (look inside nixos/tests)
  • and/or package tests
  • or, for functions and "core" functionality, tests in lib/tests or pkgs/test
  • made sure NixOS tests are linked to the relevant packages
• [ ] Tested compilation of all packages that depend on this change using nix-shell -p nixpkgs-review --run "nixpkgs-review rev HEAD". Note: all changes have to be committed, also see nixpkgs-review usage
• [ ] Tested basic functionality of all binary files (usually in ./result/bin/)
• Nixpkgs 25.11 Release Notes (or backporting 24.11 and 25.05 Nixpkgs Release notes)
  • [ ] (Package updates) Added a release notes entry if the change is major or breaking
• NixOS 25.11 Release Notes (or backporting 24.11 and 25.05 NixOS Release notes)
  • [ ] (Module updates) Added a release notes entry if the change is significant
  • [ ] (Module addition) Added a release notes entry if adding a new NixOS module
• [x] Fits CONTRIBUTING.md, pkgs/README.md, maintainers/README.md and other contributing documentation in corresponding paths.

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[marcin-serwin]

cc @NixOS/sdl @getchoo

[Aleksanaa]

testSupport feels redundant here. Why not just finalAttrs.finalPackage.doCheck?

[marcin-serwin]

Now that I look at it, these bmp files are already installed into libexec/installed-tests/SDL3 so this line should be just removed.

[uninsane]

feedback addressed:

• no more testSupport callarg. branch on finalAttrs.finalPackage.doCheck instead (this is distinct from the toplevel doCheck, in that it's forced false whenever stdenv.buildPlatform.canExecute stdenv.hostPlatform is false).
• deleted the test/*.bmp postInstall line.

confirmed that tests are still installed, and the package builds for native x86_64-linux & pkgsCross.aarch64-multiplatform.sdl3

[LordGrimmauld]

deleted the test/*.bmp postInstall line.

This causes the testtray binary to complain about missing assets. The intention was to eventually throw that stuff into VM tests, for which installing the test assets might have made sense.

[LordGrimmauld]

(a symlink might be fine though)

[marcin-serwin]

This causes the testtray binary to complain about missing assets.

This is an issue with the testtray test upstream, I've opened https://github.com/libsdl-org/SDL/pull/13252 to address this.

[LordGrimmauld]

Fair enough, and probably the better fix! Good find.

[pbsds]

This causes the testtray binary to complain about missing assets.

This is an issue with the testtray test upstream, I've opened libsdl-org/SDL#13252 to address this.

should we fetchpatch it in this PR or leave it for a followup you think?

[LordGrimmauld]

Either is fine - sdl3 gets somewhat frequent updates, so chances are it'll be there once i get around to writing those tests. I won't block on this anymore!

[pbsds]

builds when i cherry pick this and the ibus fix on master