flycheck: Always flycheck single crate if there is a build label from rust-project.json

cormacrelf · cormacrelf · commit 8d8cc93abaca · 2026-01-08T10:19:23.000+11:00
This requires us to add $saved_file / {saved_file} interpolation back to restart_for_package.
Otherwise we break existing users of $saved_file. No grand reason why we can't delete saved_file
later, although I would just leave it because sometimes a build system might really know better
which target(s) to build, including multiple targets.
diff --git a/crates/rust-analyzer/src/flycheck.rs b/crates/rust-analyzer/src/flycheck.rs
@@ -219,13 +219,14 @@ impl FlycheckHandle {
         package: PackageSpecifier,
         target: Option<Target>,
         workspace_deps: Option<FxHashSet<PackageSpecifier>>,
+        saved_file: Option<AbsPathBuf>,
     ) {
         let generation = self.generation.fetch_add(1, Ordering::Relaxed) + 1;
         self.sender
             .send(StateChange::Restart {
                 generation,
                 scope: FlycheckScope::Package { package, workspace_deps },
-                saved_file: None,
+                saved_file,
                 target,
             })
             .unwrap();
diff --git a/crates/rust-analyzer/src/handlers/notification.rs b/crates/rust-analyzer/src/handlers/notification.rs
@@ -328,6 +328,7 @@ fn run_flycheck(state: &mut GlobalState, vfs_path: VfsPath) -> bool {
                 }
                 InvocationStrategy::PerWorkspace => {
                     Box::new(move || {
+                        let saved_file = vfs_path.as_path().map(ToOwned::to_owned);
                         let target = TargetSpec::for_file(&world, file_id)?.map(|it| {
                             let tgt_kind = it.target_kind();
                             let (tgt_name, root, package) = match it {
@@ -362,8 +363,10 @@ fn run_flycheck(state: &mut GlobalState, vfs_path: VfsPath) -> bool {
                         if let Some((target, root, package)) = target {
                             // trigger a package check if we have a non-library target as that can't affect
                             // anything else in the workspace OR if we're not allowed to check the workspace as
-                            // the user opted into package checks then
-                            let package_check_allowed = target.is_some() || !may_flycheck_workspace;
+                            // the user opted into package checks then OR if this is not cargo.
+                            let package_check_allowed = target.is_some()
+                                || !may_flycheck_workspace
+                                || matches!(package, PackageSpecifier::BuildInfo { .. });
                             if package_check_allowed {
                                 package_workspace_idx =
                                     world.workspaces.iter().position(|ws| match &ws.kind {
@@ -390,6 +393,7 @@ fn run_flycheck(state: &mut GlobalState, vfs_path: VfsPath) -> bool {
                                         package,
                                         target,
                                         workspace_deps,
+                                        saved_file.clone(),
                                     );
                                 }
                             }
@@ -460,7 +464,6 @@ fn run_flycheck(state: &mut GlobalState, vfs_path: VfsPath) -> bool {
                                 ws_contains_file && !is_pkg_ws
                             });
 
-                        let saved_file = vfs_path.as_path().map(ToOwned::to_owned);
                         let mut workspace_check_triggered = false;
                         // Find and trigger corresponding flychecks
                         'flychecks: for flycheck in world.flycheck.iter() {
