From f71e6d10384de7f4458c4dfeb5eff5bec4dd4a9c Mon Sep 17 00:00:00 2001
From: Shoyu Vanilla <modulo641@gmail.com>
Date: Mon, 15 Dec 2025 23:16:08 +0900
Subject: [PATCH] fix: Prefix json target file with workspace root for sysroot
 metadata

---
 .../crates/project-model/src/workspace.rs     | 21 ++++++++++++++++++-
 1 file changed, 20 insertions(+), 1 deletion(-)

diff --git a/src/tools/rust-analyzer/crates/project-model/src/workspace.rs b/src/tools/rust-analyzer/crates/project-model/src/workspace.rs
index 10abb21ace83..747aa68f082d 100644
--- a/src/tools/rust-analyzer/crates/project-model/src/workspace.rs
+++ b/src/tools/rust-analyzer/crates/project-model/src/workspace.rs
@@ -391,6 +391,7 @@ impl ProjectWorkspace {
                     sysroot.load_workspace(
                         &RustSourceWorkspaceConfig::CargoMetadata(sysroot_metadata_config(
                             config,
+                            workspace_dir,
                             &targets,
                             toolchain.clone(),
                         )),
@@ -500,6 +501,7 @@ impl ProjectWorkspace {
                     sysroot.load_workspace(
                         &RustSourceWorkspaceConfig::CargoMetadata(sysroot_metadata_config(
                             config,
+                            project_json.project_root(),
                             &targets,
                             toolchain.clone(),
                         )),
@@ -555,6 +557,7 @@ impl ProjectWorkspace {
         let loaded_sysroot = sysroot.load_workspace(
             &RustSourceWorkspaceConfig::CargoMetadata(sysroot_metadata_config(
                 config,
+                dir,
                 &targets,
                 toolchain.clone(),
             )),
@@ -1907,12 +1910,28 @@ fn add_dep_inner(graph: &mut CrateGraphBuilder, from: CrateBuilderId, dep: Depen
 
 fn sysroot_metadata_config(
     config: &CargoConfig,
+    workspace_root: &AbsPath,
     targets: &[String],
     toolchain_version: Option<Version>,
 ) -> CargoMetadataConfig {
+    // If the target is a JSON path, prefix it with workspace root directory.
+    // Since `cargo metadata` command for sysroot is run inside sysroots dir, it may fail to
+    // locate the target file if it is given as a relative path.
+    let targets = targets
+        .iter()
+        .map(|target| {
+            if target.ends_with(".json") {
+                // If `target` is an absolute path, this will replace the whole path.
+                workspace_root.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,