fix jobserver GLOBAL_CLIENT_CHECKED uninitialized before use

compiler/rustc_data_structures/src/jobserver.rs

@@ -52,7 +52,7 @@ fn default_client() -> Client {
 
 static GLOBAL_CLIENT_CHECKED: OnceLock<Client> = OnceLock::new();
 
-pub fn check(report_warning: impl FnOnce(&'static str)) {
+pub fn initialize_checked(report_warning: impl FnOnce(&'static str)) {
     let client_checked = match &*GLOBAL_CLIENT {
         Ok(client) => client.clone(),
         Err(e) => {

compiler/rustc_interface/src/interface.rs

@@ -382,6 +382,10 @@ pub fn run_compiler<R: Send>(config: Config, f: impl FnOnce(&Compiler) -> R + Se
     // Set parallel mode before thread pool creation, which will create `Lock`s.
     rustc_data_structures::sync::set_dyn_thread_safe_mode(config.opts.unstable_opts.threads > 1);
 
+    // Check jobserver before run_in_thread_pool_with_globals, which call jobserver::acquire_thread
+    let handler = EarlyErrorHandler::new(config.opts.error_format);
+    handler.initialize_checked_jobserver();
+
     util::run_in_thread_pool_with_globals(
         config.opts.edition,
         config.opts.unstable_opts.threads,

compiler/rustc_interface/src/tests.rs

@@ -36,6 +36,9 @@ fn mk_session(handler: &mut EarlyErrorHandler, matches: getopts::Matches) -> (Se
         output_file: None,
         temps_dir,
     };
+
+    handler.initialize_checked_jobserver();
+
     let sess = build_session(
         handler,
         sessopts,

compiler/rustc_session/src/session.rs

@@ -1469,11 +1469,6 @@ pub fn build_session(
     let asm_arch =
         if target_cfg.allow_asm { InlineAsmArch::from_str(&target_cfg.arch).ok() } else { None };
 
-    // Check jobserver before getting `jobserver::client`.
-    jobserver::check(|err| {
-        handler.early_warn_with_note(err, "the build environment is likely misconfigured")
-    });
-
     let sess = Session {
         target: target_cfg,
         host,
@@ -1791,6 +1786,13 @@ impl EarlyErrorHandler {
     ) {
         self.handler.struct_warn(msg).note(note).emit()
     }
+
+    pub fn initialize_checked_jobserver(&self) {
+        // initialize jobserver before getting `jobserver::client` and `build_session`.
+        jobserver::initialize_checked(|err| {
+            self.early_warn_with_note(err, "the build environment is likely misconfigured")
+        });
+    }
 }
 
 fn mk_emitter(output: ErrorOutputType) -> Box<DynEmitter> {