rust-cbindgen: fix test failures due to env vars (#348031)

pkgs/development/tools/rust/cbindgen/1010-fix-test-failures-due-to-CARGO_BUILD_TARGET.patch

@@ -0,0 +1,56 @@
+diff --git a/tests/profile.rs b/tests/profile.rs
+index 69433a2..596829d 100644
+--- a/tests/profile.rs
++++ b/tests/profile.rs
+@@ -1,6 +1,7 @@
+ use cbindgen::*;
+ 
+ use serial_test::serial;
++use std::env;
+ use std::path::{Path, PathBuf};
+ use std::process::Command;
+ 
+@@ -17,7 +18,12 @@ fn build_using_lib(config: fn(Builder) -> Builder) -> tempfile::TempDir {
+         .tempdir()
+         .expect("Creating tmp dir failed");
+ 
+-    std::env::set_var("CARGO_EXPAND_TARGET_DIR", tmp_dir.path());
++    unsafe {
++        env::set_var("CARGO_EXPAND_TARGET_DIR", tmp_dir.path());
++        env::remove_var("CARGO_BUILD_TARGET");
++        // ^ avoid unexpected change of layout of the target directory;
++        // ... see: https://doc.rust-lang.org/cargo/guide/build-cache.html
++    }
+     let builder = Builder::new()
+         .with_config(Config::from_file(expand_dep_test_dir.join("cbindgen.toml")).unwrap())
+         .with_crate(expand_dep_test_dir);
+@@ -45,6 +51,9 @@ fn build_using_bin(extra_args: &[&str]) -> tempfile::TempDir {
+     Command::new(cbindgen_path)
+         .current_dir(expand_dep_test_dir)
+         .env("CARGO_EXPAND_TARGET_DIR", tmp_dir.path())
++        .env_remove("CARGO_BUILD_TARGET")
++        // ^ avoid unexpected change of layout of the target directory;
++        // ... see: https://doc.rust-lang.org/cargo/guide/build-cache.html
+         .args(extra_args)
+         .output()
+         .expect("build should succeed");
+@@ -87,6 +96,19 @@ fn bin_default_uses_debug_build() {
+     assert_eq!(get_contents_of_dir(target_dir.path()), &["debug"]);
+ }
+ 
++#[test]
++fn bin_ignore_cargo_build_target_in_tests() {
++    unsafe {
++        env::set_var("CARGO_BUILD_TARGET", "x86_64-unknown-linux-gnu");
++    }
++    assert_eq!(
++        env::var("CARGO_BUILD_TARGET"),
++        Ok("x86_64-unknown-linux-gnu".into())
++    );
++    // ^ this env var should be ignored:
++    bin_default_uses_debug_build();
++}
++
+ #[test]
+ fn bin_explicit_debug_build() {
+     let target_dir = build_using_bin(&["--profile", "debug"]);

pkgs/development/tools/rust/cbindgen/default.nix

@@ -23,6 +23,12 @@ rustPlatform.buildRustPackage rec {
     hash = "sha256-XTGHHD5Qw3mr+lkPKOXyqb0K3sEENW8Sf0n9mtrFFXI=";
   };
 
+  patches = [
+    # open PR: https://github.com/mozilla/cbindgen/pull/1010
+    # see also: https://github.com/NixOS/nixpkgs/pull/298108
+    ./1010-fix-test-failures-due-to-CARGO_BUILD_TARGET.patch
+  ];
+
   cargoHash = "sha256-l4FgwXdibek4BAnqjWd1rLxpEwuMNjYgvo6X3SS3fRo=";
 
   buildInputs = lib.optional stdenv.hostPlatform.isDarwin Security;
@@ -46,10 +52,6 @@ rustPlatform.buildRustPackage rec {
     "--skip test_body"
   ];
 
-  # tests currently fail, waiting on upstream
-  # Related: https://github.com/NixOS/nixpkgs/pull/348031
-  doCheck = false;
-
   passthru.tests = {
     inherit
       firefox-unwrapped