Fix regression with building dependencies

Co-authored-by: Lennard Gäher <l.gaeher@posteo.de>
Co-authored-by: Vincent Lafeychine <vincent.lafeychine@proton.me>

flake.nix

@@ -158,7 +158,7 @@
             buildInputs = [rust.toolchain pkgs.gnupatch];
             nativeBuildInputs = with pkgs;
               [makeWrapper]
-              ++ lib.optionals stdenv.isDarwin [libzip];
+              ++ lib.optionals stdenv.isDarwin [libzip libiconv];
 
             postInstall = with pkgs.lib.strings; ''
               wrapProgram $out/bin/refinedrust-rustc \

rr_frontend/Cargo.lock

@@ -435,6 +435,7 @@ name = "rrconfig"
 version = "0.1.0"
 dependencies = [
  "config",
+ "lazy_static",
  "log",
  "path-clean",
  "serde",

rr_frontend/refinedrust_frontend/tests/deps_build/Cargo.lock

+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 3
+
+[[package]]
+name = "deps_build"
+version = "0.1.0"
+dependencies = [
+ "libc",
+]
+
+[[package]]
+name = "libc"
+version = "0.2.155"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "97b3888a4aecf77e811145cadf6eef5901f4782c53886191b2f693f24761847c"

rr_frontend/refinedrust_frontend/tests/deps_build/Cargo.toml

+[package]
+name = "deps_build"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]
+libc = "0.2"
+
+[workspace]
+members = []

rr_frontend/refinedrust_frontend/tests/deps_build/dune-project

+(lang dune 3.8)
+(using coq 0.8)
+(name deps_build)

rr_frontend/refinedrust_frontend/tests/deps_build/src/lib.rs

+/// This is empty to test the build of the libc dependency, as a guard against regressions of https://gitlab.mpi-sws.org/lgaeher/refinedrust-dev/-/merge_requests/50.
+
+fn dummy() {}

rr_frontend/refinedrust_frontend/tests/runner.rs

+use std::{env, path, process};
+
+const TARGET_DIR: &str = if cfg!(debug_assertions) { "debug" } else { "release" };
+
+fn build_refinedrust() {
+    let mut cargo = process::Command::new("cargo");
+    cargo.arg("build");
+
+    let status = cargo.status().expect("failed to build refinedrust project");
+    assert!(status.success());
+}
+
+fn build_subproject(project_path: &str) {
+    let Ok(crate_dir) = env::var("CARGO_MANIFEST_DIR") else {
+        panic!("CARGO_MANIFEST_DIR must be set to find the home of the crate");
+    };
+
+    let Some(workspace_dir) = path::Path::new(&crate_dir).parent() else {
+        unreachable!("The crate `refinedrust_frontend` is inside a workspace");
+    };
+
+    let target_dir = workspace_dir.join("target").join(TARGET_DIR);
+    let path = format!("{}:{}", target_dir.display(), env::var("PATH").unwrap_or_default());
+
+    let mut cargo = process::Command::new("cargo");
+    cargo.env("PATH", path);
+    cargo.args(["-Z", "unstable-options"]).args(["-C", project_path]);
+    cargo.arg("refinedrust");
+
+    let status = cargo.status().expect(project_path);
+    assert!(status.success());
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn run_deps_build() {
+        build_refinedrust();
+        build_subproject("./tests/deps_build/");
+    }
+}

rr_frontend/rrconfig/Cargo.toml

@@ -13,3 +13,4 @@ log.workspace = true
 path-clean.workspace = true
 serde.workspace = true
 serde_json.workspace = true
+lazy_static.workspace = true

rr_frontend/rrconfig/src/lib.rs

@@ -5,18 +5,21 @@
 // file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
 use std::cell::RefCell;
-use std::env;
 use std::path::PathBuf;
+use std::sync::RwLock;
+use std::{env, mem};
 
 use config::{Config, Environment, File, FileFormat};
+use lazy_static::lazy_static;
 use path_clean::PathClean;
 use serde::Deserialize;
 
 pub mod arg_value;
 pub mod launch;
 
-thread_local! {
-    static SETTINGS: RefCell<Config> = {
+lazy_static! {
+    // RwLock due to rustc parallelism
+    static ref SETTINGS: RwLock<Config> = RwLock::new({
         let mk_config = || {
             let mut builder = Config::builder();
 
@@ -66,14 +69,14 @@ thread_local! {
             builder.build()
         };
 
-        RefCell::new(mk_config().unwrap())
-    }
+        mk_config().unwrap()
+    });
 }
 
 /// Generate a dump of the settings
 #[must_use]
 pub fn dump() -> String {
-    SETTINGS.with_borrow(|c| format!("{:#?}", c))
+    format!("{:#?}", SETTINGS.read().unwrap())
 }
 
 /// Makes the path absolute with respect to the `work_dir`.
@@ -98,7 +101,7 @@ fn read_optional_setting<T>(name: &'static str) -> Option<T>
 where
     T: Deserialize<'static>,
 {
-    SETTINGS.with_borrow(|c| c.get(name).ok())
+    SETTINGS.read().unwrap().get(name).ok()
 }
 
 fn read_setting<T>(name: &'static str) -> T
@@ -110,8 +113,10 @@ where
 
 fn write_setting<T: Into<config::Value>>(key: &'static str, value: T) {
     let builder = Config::builder().set_override(key, value).unwrap();
-
-    SETTINGS.set(builder.add_source(SETTINGS.take()).build().unwrap());
+    let mut w = SETTINGS.write().unwrap();
+    let old_settings = mem::take(&mut *w);
+    let new_settings = builder.add_source(old_settings).build().unwrap();
+    *w = new_settings;
 }
 
 #[must_use]