Merge pull request #20964 from ShoyuVanilla/canonicalize-tgts

fix: Canonicalize `custom-target.json` paths when fetching sysroot metadata

Author: Veykril

crates/project-model/src/workspace.rs

@@ -374,6 +374,7 @@ impl ProjectWorkspace {
                 sysroot.load_workspace(
                     &RustSourceWorkspaceConfig::CargoMetadata(sysroot_metadata_config(
                         config,
+                        workspace_dir,
                         &targets,
                         toolchain.clone(),
                     )),
@@ -480,6 +481,7 @@ impl ProjectWorkspace {
                     sysroot.load_workspace(
                         &RustSourceWorkspaceConfig::CargoMetadata(sysroot_metadata_config(
                             config,
+                            project_json.project_root(),
                             &targets,
                             toolchain.clone(),
                         )),
@@ -535,6 +537,7 @@ impl ProjectWorkspace {
         let loaded_sysroot = sysroot.load_workspace(
             &RustSourceWorkspaceConfig::CargoMetadata(sysroot_metadata_config(
                 config,
+                dir,
                 &targets,
                 toolchain.clone(),
             )),
@@ -1864,12 +1867,29 @@ fn add_dep_inner(graph: &mut CrateGraphBuilder, from: CrateBuilderId, dep: Depen
 
 fn sysroot_metadata_config(
     config: &CargoConfig,
+    current_dir: &AbsPath,
     targets: &[String],
     toolchain_version: Option<Version>,
 ) -> CargoMetadataConfig {
+    // We run `cargo metadata` on sysroot with sysroot dir as a working directory, but still pass
+    // the `targets` from the cargo config evaluated from the workspace's `current_dir`.
+    // So, we need to *canonicalize* those *might-be-relative-paths-to-custom-target-json-files*.
+    //
+    // See https://github.com/rust-lang/cargo/blob/f7acf448fc127df9a77c52cc2bba027790ac4931/src/cargo/core/compiler/compile_kind.rs#L171-L192
+    let targets = targets
+        .iter()
+        .map(|target| {
+            if target.ends_with(".json") {
+                current_dir.join(target).to_string()
+            } else {
+                target.to_owned()
+            }
+        })
+        .collect();
+
     CargoMetadataConfig {
         features: Default::default(),
-        targets: targets.to_vec(),
+        targets,
         extra_args: Default::default(),
         extra_env: config.extra_env.clone(),
         toolchain_version,