In reply to @qyliss:fairydust.space
there's not even anything in the compiler that needs to be fixed, just its build system

In reply to @qyliss:fairydust.space
IIRC the problem was that it didn't accomodate the possibility that you'd be building std and no_std targets at the same time.

In reply to @emilazy:matrix.org
Alyssa Ross: does this look like anything familiar? https://hydra.nixos.org/build/288008080/nixlog/1 looks like it broke when the useFetchCargoVendor cycle landed

finalAttrs.cargoDeps.patches is no longer valid (maybe null, idk can't check rn), since patches gets passed into cargoDeps.vendorStaging

there should probably be a way to pass attrs to the non-staging drv. Though, in this case we actually need to pass to the staging FOD.
So the fix is probably just using finalAttrs.cargoDeps.vendorStaging.patches

so the fix is literally just:

diff --git a/src/bootstrap/src/core/build_steps/doc.rs b/src/bootstrap/src/core/build_steps/doc.rs
index 8a9321f8e79..4bd212660dd 100644
--- a/src/bootstrap/src/core/build_steps/doc.rs
+++ b/src/bootstrap/src/core/build_steps/doc.rs
@@ -588,6 +588,9 @@ fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
 
     fn make_run(run: RunConfig<'_>) {
         let crates = compile::std_crates_for_run_make(&run);
+        if crates.is_empty() {
+            return;
+        }
         run.builder.ensure(Std {
             stage: run.builder.top_stage,
             target: run.target,

If I were to try and solve the issue of cross compiling for windows and pthreads (see https://github.com/NixOS/nixpkgs/issues/139966), what would be the best way to go about it? I would prefer to fix it so that it works with cargoBuildHook since I use that at work. Pretty much every Rust project I work on runs into this as all are crossed to Windows.

My best thought so far is to add a default CARGO_TARGET_X86_64_PC_WINDOWS_GNU_RUSTFLAGS = "-L native=${windows.pthreads}/lib" + args; or something in the build hook though I've not tried it yet.